RS232/V.10 Interface card

[M1ECY]

Probably something for Fred, but posted here for general interest as well.

In the UK there are a lot of "T1000" machines, all of these have a 6-0-6 interface as standard.

I have been repairing some of these machines over the past couple of weeks - I have been able to identify the connections to the "Line Card" from the special Cannon Connector, and have been feeding the RO machines with RS232 levels from my telegraph tester.


To interface to I-Telex, there will need to be a special interface card for RS232 - I think nothing more complicated than using a MAX232 to be driven and drive the opto that is a standard across the interfaces.

Software should allow for keyboard dialling, so I guess FSG-o-FSG will work for this application.

Also it would be very nice to be able to have the motor control feature if there are enough IO left on the interface - perhaps the on board relay of the TW 39 card could be repurposed to act as a motor contactor or SSR drive line?

I am very happy to help with prototyping of hardware and testing, but do not have the capability to deal with the software (or have access to Autocad to draw up suitable schematics)


This "New" Interface card would also work for the FS200, and probably the Hasler SP300 machines that appear from the UK Military (although 7 Bit)

There may be other machines that will also benefit from this interface,

Feedback appreciated

Cheers
Sean

[obrecht]

Hi Sean,

maybe in this context the piTelex solution for the FS200 /V.10 could also be worth to look at:

https://github.com/fablab-wue/piTelex/w ... ple_V10RPi

piTelex also allows to switch mains for the TTY to save power in standby mode.

[M1ECY]

Hi Rolf,

Thanks I will take a look at the implementation - I did briefly look at piTelex, but seeing as I already had an I-Telex system, and continue to expand the network here, it makes sense to stay with the original hardware.

There may however be an argument for the piTelex system if there is only a desire to run a single connection - there are some museums that would like to participate here in the UK, but are not interested enough to buy a system - I have some systems here in build to donate to them, but this is becoming expensive

Thanks for the link anyway.

Sean

[FredSonnenrein]

Hi Sean,

of course a V.10 interface should be easy to develop.

Some questions in the hope to get a "full" interface description:

a) You mention "6-0-6", this means that mark and space are +6V resp. -6V? Some other references mention that V.10 is identical to RS-232, but RS-232 uses up to 15 Volts.

b) Does the british T1000 use control signals to start and stop or is it like double current, where constand space means "switch off"?
As i don't have a FS200 / FS220 from TEKADE, the same question of course applies to that type.

c) Dialling information is transferred as 5-bit codes?

by the way: Using AutoCAD for drawing schematics is like using teleprinters to write love letters ;-)

Best regards,

Fred

[M1ECY]

Hi Fred,

So, to answer some questions.

a) You mention "6-0-6", this means that mark and space are +6V resp. -6V? Some other references mention that V.10 is identical to RS-232, but RS-232 uses up to 15 Volts.

This is the nominal data signalling voltages that are supplied from the telegraph interface units, however, I think (based from operational testing on the RO machine I have here) that RS232 level signals are completely fine for this purpose.

b) Does the british T1000 use control signals to start and stop or is it like double current, where constand space means "switch off"?
As i don't have a FS200 / FS220 from TEKADE, the same question of course applies to that type.

I do not have a V10 card for my FS200 to test this theory (will make schmitti richer to find out), but can confirm that the T1000 works exactly this way.

c) Dialling information is transferred as 5-bit codes?

This I am unsure of - The military T1000 was never in Telex use, purely RTTY - I cannot however see any reason that the machine would not use 5 bit - I will repair the ASR unit I have here to find out.


I will make up a simple prototype of the hardware as I see it working, and see if I can manipulate an existing copy of the interface card schematic to share here for comment - I only have Kicad for schematic and PCB work.

Thanks for the support so far

[obrecht]

by the way: Using AutoCAD for drawing schematics is like using teleprinters to write love letters ;-)

[FredSonnenrein]

Hi Sean,

b) Does the british T1000 use control signals to start and stop or is it like double current, where constand space means "switch off"?
As i don't have a FS200 / FS220 from TEKADE, the same question of course applies to that type.

I do not have a V10 card for my FS200 to test this theory (will make schmitti richer to find out), but can confirm that the T1000 works exactly this way.

To answer a question containing an "or" with "yes, exactly" does not help so much

I can offer to provide a "test firmware" to be used on the serial channel of the "combined board TW39 / serial", so that the amount of hardware work should be low...

Best regards,

Fred

[M1ECY]

Sorry Fred,

To clarify.

I do not have the V10 interface of the FS200, so cannot prove this.

The T1000 does behave in the way you suggest.

[FredSonnenrein]

Sorry Fred,

To clarify.

I do not have the V10 interface of the FS200, so cannot prove this.

The T1000 does behave in the way you suggest.

Argh. Sorry, still unclear.
Does the T1000
a) uses control lines to start / stop the printer
OR
b) uses constant space on the data line to signal "stop/idle/no connection".
OR
c) both a) and b)

Best regards,

Fred

[M1ECY]

Sorry, my confusion.

Yes, when the T1000 receives constant space condition it stops operation, and then goes into standby after 60 seconds, then when change of state happens - Traffic received, the machine restarts almost immediately.