Anleitung Ethernetkarte (englisch)

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i-Telex Ethernet interface

Description, Setup advice, User's manual

Translation based on the German version as of 2020-10-31T19:33:55‎


Preface and History

This manual will be integrated into the i-Telex Over-All Manual as soon as the author has got enough spare time.

The card was initially called i-Telex card, but should, for the sake of correctness, be rather called Ethernet Interface Card.


The Ethernet Interface Card connects the i-Telex system to the internet. It is compatible internally to all other existing i-Telex cards.

It cannot, however, be used to connect to a TxP1 member, or to an i-Telex member without an Ethernet Interface Card.

Presence of a local DHCP router is required (standard as of today).

There is also a "relay station", connecting the analogue TxP network to i-Telex on the internet.

Still, the Ethernet Interface Card can send and receive e-mail to a lesser extent.

Basics of IP Communication Between the i-Telex Stations

IP Addresses, Hostnames, Ports and Routers

Connection establishment between i-Telex stations over the World Wide Web is substantially more complex than it was in the analogue PSTN.

The adjoining graphic shows some relevant terms.

i-Telex im Internet

Internet communication is routed using so-called IP addresses. Due note should be taken that a packet's destination address can change along the transmission route. This translation is managed by routers. Every internet subscriber has got such a device (usually combined with a DSL modem).

During its transfer over the WWW, the packet has as its destination IP address the IP address of the recipient's router ( in the above example). This address is called "external IP address" from here on.

Towards the router, the Ethernet Interface Card has got a different IP address ( in the above example), which is called "lokale IP address". Most local IP addresses are inside the ranges 192.168.xx.xx or 10.xx.xx.xx. Routers employ a function called DHCP which automagically assigns local IP addresses to the attached devices (e. g. PC and i-Telex).

A packet received by the router bound for i-Telex must be forwarded to the Ethernet Interface Card. The data packet has got an additional field called "port", which enables the router to perform this task. Ports are standardised. Port 80, for instance, is reserved for web pages (HTML). i-Telex typically uses port 134. The user must configure the router such that all packets received on port 134 are forwarded to i-Telex's Ethernet Interface Card.

A further complication arises from the ISP's assignment of external IP addresses. That would not be an issue if they remained constant (like inside the local network). Usually this is not the case, as the external IP address is changed at certain points in time (like forced disconnects every 24 h).

Hence in ordinary WWW usage, a registered name ("hostname") substitutes the IP address, e. g. "". To be able to look up the associated external IP address, there are so-called "name servers" which know the allocation of names to IP addresses. In principle, everybody can have a record set up with the name servers, nevertheless it usually costs.

As a consequence, the i-Telex developers provide dedicated "name servers", hence called "member servers". Due to the fact that the teleprinters cannot dial names, the member server stores records of "i-Telex numbers" paired with external IP addresses. Furthermore, every i-Telex Ethernet Interface Card regularly sends reports to the member servers to ensure that the ISP's changes of the external IP address will be updated as soon as possible.

"i-Telex number" assignment is handled by the i-Telex developers, according to user suggestion. i-Telex numbers may have 5 to 9 digits.

The external IP address, as determined by the member server, is also saved locally inside the calling party's Ethernet Interface Card. In this local calling number list, own entries may also be created. All entries obtained from the member server may be renamed.

Own entries inside the local member list are necessary, e.g., for the e-mail sending function. This is also the case if, in one's own "domestic exchange" with multiple i-Telex stations, other teleprinters are to be called, or for calling other parties using the ASCII protocol (see below).

It's also possible to enter host names (WWW adresses) instead of IP addresses into the calling number list, e.g. "". For this to work however, the i-Telex member must have a valid WWW address, stored inside the "official" name servers.

Data Formats in the Network / i-Telex Internet Operating Modes

Communication between i-Telex members is carried out using a custom i-Telex protocol.

Alternatively, data transfer over the network can be carried out in clear text, analogue to the "Telnet" protocol. This way the Ethernet Interface Card can communicate with different network nodes, although only rudimentary, in particular only using the limited ASCII code (all characters contained in the teleprinter alphabet). Using a Telnet client, it's also possible to connect from a PC to an i-Telex connection the other way around, albeit only in this direction.

Thus every i-Telex calling number stored inside the member server's directory is of one of the following "connection types":

  1. i-Telex: another Ethernet Interface Card
  2. ASCII: other node being able to receive and send ASCII on an IP port (may also be an i-Telex Ethernet Interface Card)
  3. e-mail: any e-mail account

Concerning a. and b., the corresponding address may be one of

  1. an IP address (the external IP address of a connection or an internal IP address in case a different Ethernet Interface Card in the domestic exchange is to be called)
  2. a WWW address (if the member has registered one using an external service)

Extensions and Branches

As noted before, the i-Telex network still works by dialling an i-Telex calling number at the calling party in spite of the Internet's complex structure with hostnames, IP-addresses etc. This calling number is queried from the member directory (locally or from the servers) and is, under the hood, translated into the data necessary for establishing an internet connection (IP address and port number).

Since the i-Telex system basically also allows using multiple devices (teleprinters) in one setup (every i-Telex station is thus a domestic exchange), it has been made possible to directly call said branches.

Because i-Telex systems are frequently used by collectors which strive to operate their teleprinters as unchangedly as possible, the i-Telex calling numbers assigned to these branches aren't structured like in ordinary private branch exchanges. Telephone branch calling numbers are, for example, structured as follows:

  • "Telephone connection" calling number: 6543
  • Main branch calling number: 6543-0
  • Extension branch calling number: 6543-12

In the i-Telex network however it's not possible to discern if those "extension branches" are assigned to the i-Telex station. But inside the member directory this is obvious, namely by a numerical entry in the column "Extension". A minus inside this column denotes the main branch.

This also means that the term "calling with extension" or "calling a branch" in this manual entails an that i-Telex number whose respective entry in the member directory have a number in the "extension" column.

While making the connection, this extension is transferred to the called party which subsequently not connects the main branch, but (if allowed by configuration) the dialled extension.

A "manual" post-dial of extension numbers not listed in the member directory is not possible. Nevertheless, private records may be created in one's own local member directory.


The Ethernet Interface Card is integrated into the i-Telex system just like the other cards.

Prototype Card

To keep the board's front free of "trimming connections", the network socket is to be attached to the backplane socket connector:

Backplane Connections of Ethernet Interface Card
Pin No. Row C Row A
2…12 Bus Lines
14 NC NC
16 Ground Ground
18 Pin 2 Pin 1
20 Pin 4 Pin 3
22 Pin 8 Pin 6
24 Ground Ground
26…32 Bus Lines

A socket of type "TRJ0011" must be employed since it has got integrated line transformers!

The pins A16 / C16 as well as A24 / C24 can be used to attach "brackets" made of thick copper wire which can be soldered to the TRJ socket's metal casing.

Production Model Card

Ethernet Interface Card Assembly

In the production model card, the Ethernet network socket is on the front. On the back (backplane), no special connections are required.

Care must be taken when using a backplane with copper strips: Pins A18, C18, A20, C20, A22 and C22 must be completely insulated from each other, i. e. those pins must neither be connected with each other nor with neighbouring boards.


Start-up is conducted as follows.

Integration Into Local Ethernet

Connect the Ethernet Interface Card to the local router. For all following steps, the local IP address assigned by the router to the Ethernet Interface card must be known.

The router identifies all connected devices by the so-called MAC address. The MAC address is preset (see notice below), but can be changed.

Press the Ethernet Interface card's button long (> 1 s) to print out the local IP address, the date and a few rows of "ryryryry" on one of the teleprinters connected to the i-Telex system, e. g.:

interne ip:
datum: 12.12.2012 21:27:16

Printing can be cancelled by briefly pressing the Ethernet Interface Card's button again.

Notice: All copies of this card use the same MAC address. This isn't beautiful (put mildly), but will cause no problems as long as a router with network address translation is employed (standard) and only one i-Telex card is connected to one's own router.


To be able to establish and receive connections using the Ethernet Interface Card, the following steps are necessary:

The following settings are required for full functionality:

For setups with more than one Ethernet Card in the local network, see this checklist.

Ethernet Interface Card Set-up

All settings are changed using the configuration pages which can be accessed with any common internet browser. Enter the IP address determined in here into the address bar, e. g.

The opposite page will appear (loading the page may take several seconds…).

Main Page of i-Telex Configuration

The page consists of four parts:

  • headline: decoration only
  • menu bar: for navigating to all configuration pages, can show submenus too
  • main area
  • footer: time and date

Clicking menu bar entries either causes the menu to change (from main menu to submenu or vice versa), or the main area's content changes.

Certain functions are protected against abuse or tampering by strangers. To access these functions a password is required. As an alternative (e.&nbspg;. in case of forgotten password), the Ethernet Interface Card button may be pressed twice briefly (blue LED lights up and extinguishes again).

An unlock effected by password entry or button press lasts 5  minutes. The timespan of 5  minutes is restarted every time a protected page is loaded. The unlock affects all protected pages. Accesses from other PCs or, with an externally forwarded port 80, access is denied. (This "requesting" PC IP address check is however only performed with current system versions.)

The following sections detail the menu functions.

Menu "Information"

The main area shows static information, also containing the installed firmware version.

Menu "i-Telex"

Menu Tree

This is the entry point into the i-Telex configuration and testing pages. Pages are designed bilingually, so the menu entry "i-Telex" is present in German and English language.

Hereinafter, only the German version will be presented and explained. Passwort-protected pages are marked in grey.

The menu under i-Telex is structured as opposite.

Menu "Send Message"

Page "Send Message"

This function allows easy testing of the installation. When selecting this menu item, the main area splits in two parts. The upper (bigger) part is a "mirror" of the teleprinter, the lower part is used to enter text line by line, being sent to the teleprinter connected to i-Telex after pressing "Send". It's also possible to enter text on the teleprinter, the former will be output in the upper main area.

Entering an "@" as only or last character in the sending box triggers the answerback unit.

The percent sign (%) works similarly as it will trigger the teleprinter's bell (entered at any position).

The printer mirror in the upper main area is updated automatically every 10 seconds, but may also be updated manually by clicking the link "Update" in the lower main area.

The teleprinter will be stopped 20 seconds after the "Send Message" window is closed, or 5 minutes after the last character has been sent or received. From version 748, the connection may be terminated immediately by entering & (as the only character in the line).

After the connection has been terminated, the connection between HTML page and teleprinter can only be remade by entering and sending another text.

Notice: In case another WWW user opens this page he will see the same text output. This allows multi-point communication, but also unsolicited reading by unknown third parties!

Menu "Member Directory"

Chapter 3 details the member directory's purpose. The member directory thus stores the calling numbers (diallable from the teleprinter) in conjunction with the matching addresses and other information. The internally connected devices must not be entered!

The member directory can be saved to a dedicated EEPROM on the board, the data are thus retained on mains failure. To this end, select "save non-volatilely" (see below).

Beyond that, the central member servers contain a "global" telephone directory. The local Ethernet Interface Card queries this "global" directory under specific conditions and saves a copy of the record in its own memory. The "global" numbers mus be at least 5 digits long. Member server query is performed when at least five digits have been entered and two seconds have passed without another digit.

So the sequence is as follows:

Dial Flowchart
  • The calling party dials another i-Telex member's calling number (consisting of at least five digits). After the last dialled digit (determined by a dialling pause of at least two seconds) the Ethernet Interface Card queries the member server if this number is known. If it is, the member server transfers the called party's record (IP address or the like) to the calling party, where this record is saved, too. The calling Ethernet Interface Card will then connect to the i-Telex called party.
  • If the dialled number doesn't exist in the member directory, nothing happens, so it's possible to continue or cancel dialling.
  • But if the dialled number is present in the local member directory and the member server query isn't immediately successful, the local data will be used to connect to the called party.

Entering custom (local) calling numbers is only necessary in case of "special" connections, e. g. for e-mail or ASCII connections.

The member directory is displayed opposite.

  • Calling number is the number to be dialled on the teleprinter to connect to the respective member. This number is to be dialled after the "line access number". It may be from 1 to 9 places. Leading zeroes aren't allowed. Be advised that a dialled number is accepted as soon as it fits at least one of the records. So the following set-up is problematic:
    • number 123 for member A
    • number 1234 for member B
    Member B can never be dialled since, while trying to, after dialling the digits 123, member A matches. A possible workaround would be to assign 1230 to member A.
  • Name is a freely assignable name to facilitate recognition of this record. The name may be 40 characters long. This name is used with the member directory information service.
  • Peculiarity: "Local" in this column means the record is stored as being valid only internally. "DynIP" means the respective record has been queried from the member server and the latter has a "changing" IP address. DynIP records can only be created by administrators on member servers.
  • Type Connections can be established using different protocols. "i-Telex", "ASCII" and "eMail" are currently implemented. "Deleted" marks deleted records or an old calling number of modified records.
  • Address contains the member's URL or the global IP address or the e-mail address. It may be up to 40 characters long.
  • Port signifies the TCP port through which the member can be reached. Normally this is 134. Filling in this column is mandatory for, and only makes sense with, record types "i-Telex" and "ASCII".
  • Extension determines if the caller should directly dial a specific device (instead of the "main branch" defined there; see also here). Entering a value here only makes sense with records of type "i-Telex". The extension must be enabled at the called party. For details, see here.
  • Last Update indicates when the record was last modified, e. g. automatically with dynamic records or after a manual change has been preformed.
  • Click Update to modify or delete an existing record.
  • Click Add to create a new record in the member directory.
  • The headings of columns calling number, name and last update exhibit a "sort up down", respectively. Click "up" or "down" to sort the table up or down by the respective column.

Below the table, further functions can be selected concerning the whole member directory:

  • Click save permanently to save the whole member directory in a special EEPROM chip on the Ethernet Interface Card. Only then, all changes will be safe in case of power failure! Only the current state is saved, subsequent changes will only be saved to RAM. On system reboot (by turning on supply voltage or by rebooting manually), the EEPROM contents will be loaded into RAM again.
  • Click abandon all changes to clear the member directory and load the state last saved to the EEPROM.
  • Click erase completely to clear the member directory; it will be empty afterwards. This doesn't concern the content of the Ethernet Interface Card's EEPROM chip, the latter will only be written to or erased by clicking save permanently.

When deleting records or changing member calling numbers, the old number will be retained in the list with its type changed to "deleted".

When clicking Update or Add, the configuration password prompt may appear. After entering it the member directory will be displayed again. The action clicked beforehand must then be selected again to be effective. After that, the opposite window will appear.

Member Directory Entry Form
  • The boxes Calling number, Name, Type, Address, Port and Extension have already been explained above.
  • By selecting "deleted" as type the record will be marked as deleted after clicking Update.
  • The local only checkbox protects the record from being overwritten by information retrieved from the member server. On the member server itself this entails that the record will not be issued to clients.
  • The locked checkbox, if ticked, will ensure that a record is saved, but will never be applied, even though a matching number has been dialled.
  • Click Member Directory to discard the form and display the member directory again.

Menu "i-Telex Settings"

This menu item will open a submenu with 6 items.

Menu "i-Telex Settings – Local System Settings"

This page is only present in early versions of the Ethernet Interface Card and, in more current versions, has been split into the following pages:

Menu "i-Telex Settings – Local Device Configuration"

The settings on this page resemble, in parts, the settings of i-Telex's analogue Interface card.

Ethernet Interface Card Local System Settings Form

Network Prefix for Outgoing Connections is the "Line Access Number" that must be dialled while connecting to another i-Telex member prior to the latter's calling number from the member directory (preset is 66). The number may have one or two digits.

Fixed Main Branch for Incoming Connections: Enabling this button causes all incoming calls to be routed to the same extension (main extension). If this option is disabled, incoming calls will be routed to the extension from which the last outgoing call through the Ethernet Interface Card originated or which has last been addressed by a call without any particular extension.

Main Branch's Internal Extension for Incoming Connections: Enter the local extension for the main branch here. If "fixed main branch" isn't active, this setting shows the extension of the branch active last.

Call Forwarding Busy: If the branch addressed by an incoming extension is unavailable, this setting determines if the call may be "forwarded" to a different branch. Three alternatives are available:

  • Never: If a call arrives for the busy main branch or another busy branch (if direct dialling is being used), the calling party will be signalled occupied ("occ")
  • Main Branch Only: Calls to the busy main branch will be forwarded to other branches, direct dialling calls to busy branches will be rejected with a busy signal.
  • Also for Direct Dial: All calls to busy branches will be forwarded to another branch.

When trying to forward, beginning with the main branch, the next numerically available local branch will be dialled, provided that "refuse forwarding" hasn't been configured for the respective branch. This entails that branches may possibly be dialled which aren't included in the "Permitted Branches".

Example: The main branch number is specified as 31, the caller has dialled the number for extension 45. The ethernet-board will try to access the interfaces in the following order: 45 (as the dialled extension), 31 (as the main branch number), 32 (as the numerical following number), 33, 34, 35, ..., 99, 00, 1, 2, 3, 4, 5, ... 9, 01, 02, ... 30.

In versions before 757 this setting is called Alternative Search on Busy and consists only of a "checkbox". Turned off, it means "never" as above, when enabled its function is "Main Branch Only". "Also for Direct Dial" is not available in these older versions.

Permitted Branches: Enter here which own devices, apart from the main branch, may be dialled directly from outside. The example above, "31,33,55,44,80,81,82,83,0", causes the extensions 31, 33, 55, 44 and 80 to 83 to be available for direct dial. Moreover, the order of the entries is significant, too, since the calling party may use "speed dial" as follows. If he dials the extension 2, i-Telex translates this to 33 because 33 is in the list's second place. Likewise, 55 can be called using the extension 3. This option has been provided to allow changing the local extensions without having to communicate this to "external callers" because, as a general rule, only single-digit extensions should be used from outside.

No more than 9 direct dial extensions / branch extensions are possible.

From version 731 onward, prepending a # changes the list into a prohibited list. For instance, #82,83 prohibits incoming calls to the devices with the branch extensions 82 and 83, to all others calls are permitted. In this case, sequence is of no significance.

Module Baud Rates: This function is available from version 900. The Ethernet Interface Card now supports speeds different from 50 Baud. The respective devices' baud rates must be given in an allocation list. This list will be explained using the following examples:

Entry Meaning
*:50 All devices are 50 Bauds
61:100, *:50 Device with extension 61 is 100 Baud, all others 50 Baud
70-79:75, 61:100, *:50 Branch 61 is 100 Baud, the devices with extensions 70 until 79 are 75 Baud, all others 50 Baud
35-37:50, *:45 Branches 35 to 37 are 50 Baud, all others 45 Baud

The statements will be evaluated from left to right, which is why the * statement must be last. Spaces used for visual arrangement may be omitted. Only the separators shown in the examples may be used: -, : and , After clicking "Confirm Settings", error positions will be pointed out, if any. All baud rates are allowed that can be calculated as 900 / x where x is integer and at least 5, which includes 100 Baud, 75 Baud, 60 Baud and 50 Baud. Even though 45.45 Baud is no integer divider, but the difference from 45.0 is sufficiently small.

Note: This option does not allow connecting internal devices with different baud rates.

Use New Internal Bus Protocol: This function (available only from Build 900) should only be used in case a connected device exhibits especially long start-up times (more than 1.5 seconds). In this case, all interface cards must have software version 450 or newer. These versions allow configuring a respective delay. If this option is active and a connection is being established with an interface card of too old a version, the connection will fail.

Menu "i-Telex Settings – Local Operations Settings"

Automatically print date on call: Select if date and time should be printed automatically on incoming calls. Selectable options are disabled, only for caller, only for self, or on both sides.

It's not possible to control if, on outgoing calls, the callee will print time and date.

Automatic linebreak in column: For connections from and to "external systems" a (possibly automatic) line break can be enabled in the column specified here.

Distribute time to other modules: Various (recent) i-Telex modules use time of day. This option enables the Ethernet Interface Card to distribute time throughout the system. Turn off only if faults take place regularly in the own system.

Logging level for serial interface: Configure the amount of information to be output on the serial interface during incoming and outgoing connections and other activities. The following settings are available:

0: no logging
1: log errors
2: log all basic procedures
3: log complete data traffic with telegram lengths
4: log complete data traffic with telegram contents
5: also log periodic activities

Logging level for member server: For all member server interactions. (eliminated in newer versions)

0: no logging
1: log errors
2: log all basic procedures
3: log complete data traffic with telegram lengths
4: log complete data traffic with telegram contents
5: also log periodic activities
0: keine Protokollierung

Logging level for teleprinter output: Configure what diagnostic information is sent to the connected teleprinter(s). The following settings are available:

0: none
1: internal (critical) errors impairing operation that should be corrected (e. g. incorrect settings)
2: like 1 and external errors (e. g. member server connection errors). These external errors may correct themselves on next try.
3: like 2 and including operator errors or simple errors (e. g. unavailable calling number dialled, callee busy)
4: like 3 and status reports (e. g. second incoming call on existing connection)
5: all TCP accesses are logged.

Password for configuration pages: Enter the password that will protect all important setting dialogues from unauthorised access. This password is especially advisable if the router's http port 80 is being forwarded to the Ethernet Interface Card to serve the i-Telex HTML pages to the internet. In case the password has been forgotten, all configuration pages are locked, but by shortly pushing the button on the card, entering the valid password will be "simulated". Since pushing this button also enables call barring (blue LED), a second short push is advisable to "unlock" the Ethernet Interface Card.

Member directory visible for everyone: If this button is enabled, everyone that can open the page "member directory" can see all records. If inactive, to view the local member directory the configuration password must be entered. On Ethernet Interface cards that work as member servers, "global" records are always visible.

Service messages in long form: If this button is enabled, after a connection attempts has failed, a verbose message will be printed on the dialling teleprinter (e. g. line busy). If it is disabled, only an abbreviation will be printed (e. g. occ). here. When enabling this button, "Logging level for teleprinter output" should be set to at least 2 because otherwise the messages will be filtered out. If set to 2, all service messages "out of the ordinary" will be printed, but not "busy" and "disconnected" (waited too long during dial). If set to 3, all terminations will be "illustrated" with a service message.

Menu "i-Telex Settings – Settings for i-Telex Network"
Ethernet Interface Card Settings Form for the i-Telex Network

Own i-Telex calling number: The Ethernet Interface Card reports this number to the member server. The i-Telex calling number should be consented to by the i-Telex developers. Every new i-Telex calling number must be activated on the member servers which can only be performed by administrators.

Secret number for member server login: To prevent abuse a secret number must be chosen, which is checked upon sending an update to the member server. It must be a number in the range of 1 to 65535. This number stays secret, but will be stored upon updating after the record has been activated by the member server administrator, as future reference. Changes to the secret number have to be arranged with a member server administrator.

Public port number: Enter the port facing the internet that is forwarded by the router to the Ethernet Interface Card here. Typically, 134 is appropriate. Important: Changing this number only has influence on the record on the member server, and only if dynamic IP update is enabled. When setting up the router (port forwarding, see here), "local port" always has to be 134, even though "public port number" is set to a value different from 134. This box is meaningless if dynamic IP update is disabled or "permanent connection" is being used.

Dynamic IP update enabled: Only if this option is set one's own IP address record will be updated periodically on the member server. Usually enabled if no dedicated hostname is being used (like, for instance, The option should be turned off if the own calling number is saved in the member directory with a personal hostname.

Connection test period: To test if the IP address recorded on the member server is still valid, the Ethernet Interface Card will periodically call itself. The number entered here determines the self-calling period in seconds. In rare cases it makes sense to disable this self-calling function by entering 0 (zero). This setting is only effective if "dynamic IP update" is enabled.

Use permanent server connection due to non-public IP: This option enables (since version 825) users without a public IP address to use i-Telex. If enabled, i-Telex will permanently connect to a member server. This member server will then "pass on" any incoming connection. This option must only be used if consented to by a member server administrator. For funcional reasons, this option precludes use of the option "dynamic IP update".

Member server address: Enter the member servers' addresses into the three boxes. Provided that only one or two member servers exist, addresses should, if applicable, be entered multiple times.

Secret number for server synchonisation: Is only relevant for i-Telex systems set up as member servers. Please leave at 0. In later versions, this box will be eliminated.

Note: On setting up a new i-Telex line utilising an Ethernet Interface Card, the calling number chosen will immediately be reported to the member servers, but has to be activated beforehand. To this end, please notify the administrators accordingly.

Menu "i-Telex Settings – Imprint"
Form for setting the imprint

The imprint can be entered and changed here. The imprint may consist of up to 10 lines.

Below the input boxes "line to change" and "new text", the current imprint is shown alongside line numbers. To change a line, enter the respective line number and the corresponding text. The change will be committed upon clicking "Apply setting". The input boxes stay unchanged so that small corrections can be performed.

When entering the line number only, leaving blank the "new text" box, then "apply setting" will only copy the existing line into the input box "new text" (to facilitate changes). To actually delete an existing imprint line, enter the line number and a single minus - into "new text".

"New text" may also be HTML code. For instance, <b>bold</b> will yield bold text. A link may be entered like so:

<a href=\"\" target=\"blank\">i-Telex-Homepage</a>

Using target=\"blank\" makes sense if it is desired to open a new window upon clicking it. For correct HTML code, some characters have to be entered in a special way:

< as &lt;
> as &gt;
& as &amp;
Menu "i-Telex Settings – E-Mail Settings"
Form for Ethernet Interface Card E-Mail Communications Settings

The Ethernet Interface card is able to send and receive e-mail. Receiving requires the e-mail to be formatted as plain ASCII (plain text).

An e-mail account must be set up on an e-mail server supporting POP3 and SMTP. SSL is not supported.

POP server address: Enter the incoming mail server's address.

SMTP server address: Enter the outgoing mail server's address. Often identical to the POP server.

Own e-mail Address: Enter your e-mail address.

E-mail server password: Enter the password for accessing the mail server.

E-mail retrieval frequency (minutes): Configure here how often the mail server will be checked for new messages. Entering nought to disable retrieval.

Only print e-mails with +TX+ in subject: To fend off SPAM, enable this option which causes only those mails to be printed that contain "+TX+" or "+tx+" at an arbitrary position in their subject. When sending, this label will always be appended (to the subject line).

Menu i-Telex Settings – Network – Information"

Shows Ethernet connection data. No input possible.

Menu "i-Telex Settings – Network – Configuration"

Network connection settings may be modified here. Generally, it shouldn't be necessary to change anything. All changes are only effective after restarting the Ethernet Interface Card.

With DHCP enabled, the settings IP address, subnet mask, gateway and DNS server aren't required, or rather will have no effect.

After changing the hardware MAC address with DHCP enabled, due note should be taken of the fact that the router will issue a new IP address to the Ethernet Interface Card as soon as it has been rebooted.

Menu "i-Telex Settings – System – Reset"

Clicking the button "Reset" causes the card to reboot just like after a power failure.

Menu "i-Telex Settings – System – NTP"
Form for Time Server Settings

Enter the information necessary for the Ethernet Interface Card to automatically retrieve the time of day from a central time server.

Until version 809 however, unlike "NTP" suggests, not the modern NTP (Network Time Protocol) was used, but a "Time Protocol Server" according to RFC 868 from which the time information may be queried over TCP/UDP port 37. By far, not all time servers accessible on the internet serve this much older protocol. Tried-and-tested servers are:


and inside the "HAMNet", the ham radio intranet, the time server

If using a different time server is desired, it can be tested with a Telnet client: If the server responds to a connection attempt on port 37 (with four special characters), it is suitable. Since version 811 however the "modern" NTP protocol is being used.

Query time from server: Turn automatic clock adjustment on or off here. Since manually setting the time isn't possible this option should be enabled.

Time server hostname: A time server's hostname, e. g. "".

Timezone: The time shift relative to UTC, for Central European Time +1.

Automatic Daylight Saving: Check this box to automatically adjust the clock to daylight saving time and back, in accordance with published rules.

After clicking "Apply setting", the system will display if the time server has been queried successfully along with the current system time.

The 'footer' time display is only updated roughly every 5 minutes!

Menu "i-Telex Settings – System – DynDNS"

Description to be done, function is only necessary in special cases.

Menu "i-Telex Settings – System – EEmem"

Description to be done, function is insignificant.

Menu "i-Telex Settings – System – cron"

Description to be done, function is insignificant.

Menu "i-Telex Settings – Lock"

Click this menu item to lock the configuration pages so that the password must be entered again. Locking will also take place automatically as soon as a period of 5 minutes has passed after the last configuration page access.

Menu "Debug Information"

Description to be done, function is insignificant. Only required for diagnostics.

Menu "Bus Stn List"

This menu item enables checking which interfaces are attached to one's complete i-Telex system.

In idle state all addresses (local extensions) should exhibit status 80 (for device interfaces), 90 (for special interfaces, e. g. test transmitters) or A0 (for line interfaces).

In case different codes are being displayed, the respective module is not in initial state and should be restarted if appropriate.

Menu "SD Card"

Only works if an SD card is attached at the extension port. Function insignificant. Only required for diagnostics.

Menu "Imprint"

The imprint entered in the form above is displayed here.

Reset to Factory Settings

The Ethernet Interface Card's customised settings can also be reset to factory settings without accessing the web interface. This requires adhering to the following procedure:

  • Reboot the Ethernet Interface Card by turning power off and on. (If the card ha booted successfully before, a reboot by button might work: Press shortly -- blue LED lights up -- press again long.)
  • Now the Ethernet Interface Card runs its self-test routine, recognisable by lighting up of the red, yellow and possibly the green LED.
  • Before the self-test is finished press the button again and hold down until only the yellow LED is lit.
  • Release button, the yellow LED goes out, the red one lights up.
  • Now begins a pause of three seconds duration during which one of the following actions are possible:

Turn on DHCP

If the button is pressed briefly during the three-second pause, only the DHCP option will be enabled.

The button press will be confirmed by the green LED, the change will be confirmed by the yellow and blue LEDs lighting up for one second. Afterwards, the Ethernet Interface Card will reboot.

This action makes sense if DHCP has accidentally been turned off as described above, or if a fixed IP address has accidentally been assigned that isn't inside the router's address range.

Factory Resetting all Customised Settings

If, during the three-second pause, the button is pushed again and held down for another three seconds, all settings will be reset to factory state.

As before, the green LED will confirm the button press, after 2 seconds the blue will light up too (the button must be kept depressed still), the change will be confirmed by the yellow, green and blue LED lighting up for one second. Afterwards, the Ethernet Interface Card will reboot.

This action makes sense in case all customised settings should be erased. To restore the Ethernet Interface Card to full working order, all settings must be entered again as described above.

Continue Booting

If the button is not pressed during the three-second pause, no changes are made and booting will continue normally.

Setting Up Port Forwarding

Port Forwarding must be configured on one's own router so that it can forward incoming connection requests to the Ethernet Interface Card.

No port forwarding is necessary if the option "Use permanent server connection due to non-public IP" is enabled.

Use port 134.

The router manual contains instructions on how to set up the necessary options.

The exact router settings aren't clearly describable due to the range of models, but the following information should suffice:

Essential Port Forwarding Router Settings
Setting Value
Protocol TCP
IP Address (or LAN IP Address) Ethernet Interface Card's local IP address, see above
Port (or WAN port, external port) 134
To port (or LAN port, internal port) 134
Name (insignificant, label only)

Port 80 may also be forwarded so that the Ethernet Interface Card is accessible by every browser worldwide. But then it is advisable to enable password protection for the configuration pages (see above)!

Multiple Ethernet Interface Cards in Local Network

A few things must be taken into consideration if multiple Ethernet Interface Cards are to be used inside the LAN. This applies irrespective of whether two or more Ethernet Interface Cards should be installed in one i-Telex system, or whether there are separate i-Telex systems planned.

  1. The new Ethernet Interface Card must be assigned a new MAC address:
    1. Disconnect the "old" Ethernet Interface Card temporarily from the LAN.
    2. Change the existing MAC address (slightly) in "i-Telex Settings – Network – Configuration" (see here) and restart the card afterwards. If DHCP is being used this will result in a changed IP address being assigned.
    3. The "old" Ethernet Interface Card can now be reconnected to the network.
  2. Determine the new Ethernet Interface Card's IP address or set up a fixed one.
  3. Pick a "free" public port number (e. g. 133).
  4. Set up the following port forwarding in the router just like above.
    1. Public port 133 (see 3.) to new card's local IP address, port 134.
    2. (optional) Public port 81 to new card's local IP address, port 80.
    Note: The local port number for i-Telex communication is always 134, regardless of the card's settings.
  5. If dynamic IP update is to be used: Enter the port number chosen in step 3 (e. g. 133) into the box "public port number" on the page "i-Telex Network Settings". Needless to say, enter a different number into "own calling number".

During Operation


LED Indications
LED Meaning
Red Blocked due to internal procedures
Yellow (upper) Steady: outgoing connection established
Flicker: In case of incoming connection, signal transmitted to local device
Green (upper) Steady: incoming connection established
Flicker: In case of outgoing connection, signal transmitted to local device
Blue Steady: connection block
Flicker: signal received from local device
Yellow (lower) Flicker: data being sent/received in Ethernet
Green (lower) Steady: network connection to router established (electrically), normally lights continuously.

On the production model card, the lower LEDs are integrated into the network socket.

The upper 4 LEDs mean the following:

Device Interface Indications

LED off
LED on
LED flashing or flickering
◌   ◌   ◌    idle state
●   ◌   ◌    data processing blocks other functions
◌   ◌   ◌    function block (brief push turns on and off)
◌   ●   ◍    outgoing connection initiated or established
green: signal transmitted
blue: signal received
◌   ◍   ●    incoming connection established
yellow: signal transmitted
blue: signal received


A brief button press turns off the interface (function block, module disabled). Turn on again by pushing the button again briefly. Coincidently, pushing the button will unlock the configuration pages' password protection.

Whilst the blue LED is off, a long push will trigger printing the local IP address and date. If the blue LED is lit a reset will be initiated.

Further operation is performed using the attached devices or the settings described above.

Reports After Failed Connection Attempt

If dialling fails, one of the follwing shorthand symbols will be printed, meaning the following:

Reports After Failed Connection Attempt
Shorthand Meaning
occ The line dialled is busy
nc The line dialled is unavailable
na The line dialled is not allowed (invalid direct dial number)
abs The line dialled is disabled temporarily
bk Dialling has been cancelled due to time-out

Instead of those shorthands a longer text will be printed if "Service messages in long form" is enabled (see above).

Sending E-Mail

After dialling the i-Telex calling number assigned to an e-mail address, the subject will be asked for. Complete with carriage return.

Enter the main text after a respective prompt has been printed. To post, press the disconnect key. Cancelling is not possible.

When dialling a member directory record with e-mail address ? (question mark only), the actual e-mail address must be entered before the subject prompt. Enter the recipient's e-mail address on the teleprinter, typing the oblique / instead of the @ sign.

Example for posting an e-mail, including prompt for recipient's e-mail address:

email to: henning/
subject: my message to henning
please write back whether you've received this mail.

Member Directory Information

A directory information has been implemented so that it's not necessary to memorise all calling numbers of registered i-Telex users.

The directory information function will be started after dialling a nought instead of an i-Telex calling number. After the prompt, enter a search term at least four characters long.

As a result, all member directory records will be output, including number and additional information, whose name contains the (entered) search term anywhere. Beforehand, the member server will be queried and matching records will be transferred into the local member directory.

Messaging Over HTML Page

See here. The Ethernet Interface Card's HTML pages are accessible from the whole WWW if port 80 is being forwarded. This way, everyone might, using a common internet browser, leave messages on the teleprinter, or if the owner is preset "chatting" with each other is possible. Problem: In order to do this, the user must know the intended i-Telex member's current external IP address. Only by using a dynamic DNS service (e. g. or a "permanent" hostname can be assigned. These dynamic DNS services may require an account (possibly fee required), furthermore the own router must be set up accordingly.


Bestimmte Fehlermeldungen werden auf den angeschlossenen Fernschreibern ausgedruckt. Die Bedeutungen der Fehlermeldungen sind (in alphabetischer Reihenfolge):

  • falsches konfigurations-kennwort eingegeben: Jemand hat versucht, auf die Konfigurationsseiten zuzugreifen und hat dabei ein falsches Kennwort eingegeben.
  • fat_...: Interner Fehler beim Zugriff auf eine angeschlossene SD-Karte. Vermutlich SD-Karte voll oder SD-Karte hat Dateisystem-Fehler.
  • fehler im zusatz-eeprom: Hardware-Fehler am Zusatz-EEPROM für das eigene Teilnehmer-Verzeichnis. Fehlerbehebung: Das Teilnehmerverzeichnis nicht flüchtig speichern (siehe Abschnitt
  • gewaehlte nummer nicht bekannt: Die gewählte Nummer wurde weder im eigenen, noch im gemeinsamen Teilnehmer-Verzeichnis (des Teilnehmer-Servers) gefunden.
  • interne verbindung unterbrochen: Während einer aufgebauten Verbindung brach die Kommunikation zum lokalen Endgerät ab. Behebung: Verbindung nochmals aufbauen.
  • internes rufnummern-verzeichnis voll: Der Speicher für die Teilnehmer-Rufnummern ist voll. Behebung: unwichtige / abgelaufene Einträge löschen.
  • keine verbindung zu allen teilnehmer-servern: Die Ethernet-Schnittstellenkarte hat keinen der definierten Teilnehmer-Server erreicht. Dies ist ein Zeichen dafür, dass vom eigenen Router über einen längeren Zeitraum das Internet nicht erreichbar ist.
  • keine verbindung zum mail-server fuer ausgang: Für eine beabsichtige Sendung einer Email konnte der Mail-Server nicht erreicht werden. Behebung: Einstellungen für den Mail-Server überprüfen und nochmal versuchen.
  • mail in dieser version nicht unterstuetzt: sollte nicht vorkommen
  • mehrfache fehler beim senden ins netz: Auf der Netzwerk-Verbindung sind Übertragungsfehler eingetreten, jedoch konnte die Verbindung wiederhergestellt werden.
  • reservierung fuer einschaltung konnte nicht versandt werden: Bei einem kommenden Verbindungsaufbau konnte keine Verbindung zum gewünschten lokalen Endgerät hergestellt werden. Prüfen, ob Endgerät eingeschaltet und erreichbar ist (blaue LED der Schnittstellenkarte?) und Verbindungsaufbau nochmals versuchen.
  • selbst-anruf mehrfach versagt, router-konfiguration pruefen: Die Ethernet-Schnittstellenkarte kann die Verbindung ins globale Netz nicht prüfen. Bei manchen Routern tritt dieses Problem ständig auf, dann ist die Verbindungstest-Periode (s. Abschnitt auf null zu setzen. Ansonsten ist zu prüfen, ob beim Router die Port-Weiterleitung für ankommende Verbindungen korrekt gesetzt ist (s. Abschnitt 5.5).
  • smtp-server konnte nicht verbunden werden: Der festgelegte Server für das Absenden von Mails ist vorübergehend nicht erreichbar. Nochmals probieren und ggf. die Server-Adresse überprüfen (s. Abschnitt
  • smtp-server: ip nicht ermittelbar: Der festgelegte Server für das Absenden von Mails ist nicht erreichbar. Vermutlich ist die Adresse falsch eingegeben (s. Abschnitt
  • teilnehmer nicht erreichbar: Der angewählte i-Telex-Teilnehmer ist momentan nicht erreichbar.
  • vom smtp-server: …: Eine Fehlermeldung des Servers für abzusendende E-Mails. Der weitere Text der Meldung sollte einen Anhaltspunkt für die Fehlerursache geben.
  • zeitueberschreitung bei wiederaufnahme der verbindung: Während einer Verbindung zu einem anderen i-Telex-Teilnehmer ist die Netzwerk-Verbindung unterbrochen wurden. Später nochmals versuchen.
  • zweiter kommender anruf auf belegtem telexphone-socket: Während einer bestehenden Verbindung erfolgte ein zweiter Anruf. Dies ist somit das Kennzeichen dafür, dass ein anderer Teilnehmer nicht durchgekommen ist. Sporadisch kann diese Meldung auch eintreten, obwohl keine andere Verbindung bestand.

Bekannte Fehler

  • Die Meldung reservierung fuer einschaltung konnte nicht versandt werden sollte bei nur besetztem Endgerät anders formuliert werden.
  • Die Meldung teilnehmer nicht erreichbar kann auch kommen, wenn die Verbindung erfolgreich aufgebaut wurde. Grund: Hat sich die IP des gerufenen Teilnehmers zwischenzeitlich geändert, wird vom Rufenden zuerst vergeblich eine Verbindung zur alten IP des Gerufenen aufgebaut, diese danach aber mit den vom Teilnehmer-Server aktualisierten Daten doch erfolgreich hergestellt. Vom ersten Versuch bleibt aber die Diagnosemeldung zurück.
  • Die Meldung zweiter kommender anruf auf belegtem telexphone-socket erscheint, wenn sich zeitlich ein Selbstanruf und die Mail-Abfrage überschneiden.
  • Sehr lange E-Mails werden nicht korrekt, sondern ggf. mehrfach gedruckt (weil die Verbindung während des Druckens abstürzt).


Datum Inhalt Firmware-Version
12.07.2018 Beginn der Versionsaufzeichnung
15.02.2019 „echtes“ NTP-Protokoll ab 811
15.02.2019 Option Standverbindung ergänzt ab 825