Siemens Modem Communications

We are trying to set up a modem communications link to a system in northern Spain. We are currently testing it in-house, and we are having no success. We have an inquiry into Siemens tech support, but they have not deigned to respond yet. Can someone on the forum give us any pointers or tricks that could get us started?

Hardware:
Westermo modem Model TD33
Siemens TS adapter, 232/MPI/DP
PLC Siemens CPU 315

Software:
Programming Step 7 S7/M7/C7 Ver 5.2
Siemens TesleService Pak Ver. 5.2
OS Windows XP Professional Version 2002 Service Pak 1

Communications parameters are at defaults, modem is set to autodetect parameters.

The laptop dials out, the modem answers, we get a steady DCD (Data Carrier Detect) LED on the modem, and the modem RD (Receive Data) LED blinks. After a couple of seconds the connection is broken, and the TeleService software gives us the following error message:

"The job was aborted owing to a transfer error to the TS adapter."

Any help would be greatly appreciated.

Thanks,

Tom

Still no response from Siemens. Have any of you guys done modem downloads to a Siemens system?

Hi Tom,

I've never tried to interface with Siemens, but found this on the net, maybe it will give some help.... http://www.sixnetio.com/html_files/tech_notes/tn644.pdf

The part that kinda leapt out at me was page 7, connecting the hardware. Apparently, the serial cable is crossed, so you need to use the MDM cable. With pc networking, you get a similar error when trying to use a straight through cable instead of a crossover to connect 2 pc's....

Hope this helps.

Hoot

Thanks, Hoot. We'll try testing some more today.

Tom

Hi Tom,

this is what I found on Siemens Supportpage.

I think it's short enough, so i post it directly

Beitrags-ID: 15390529
Datum: 09.07.2003

---
QUESTION:
I established an AS-AS-Remote coupling by means of two adaptors and two modems. The configuration of the modem connection and the subsequent remote data transfer work properly. When deactivating the modem connection via the FB „AS_DIAL“, the FB „AS_DIAL“ is closed without any error message, however, the modem connection is still active, why?

ANSWER:
You are probably using a modem, of which the default parametrization is ignoring the status change at the DTR signal input (e.g. a Modem of "Westermo").

Remedy:
Enlarge the initialization string in the TS Adapter in this way that the modem does execute a connection interruption when changing from DTR -> OFF .
This is generally done with the additional AT-command: „&D2“ (details can be obtained from your modem manual).

Example:

Initstring within the TS Adapter before the change:
AT&FE1L1M1Q0V1&C1S0=1
Initstring within the TS Adapter after the change:
AT&FE1L1M1Q0V1&C1&D2S0=1

---
HTH

Rolf

I have used the sixnet modems for
communications with our machines
in China. VT-MODEM-1WW works as
good as the telephone lines being
utilized. There is also a good
example provided to follow setting
up the modem and teleservice software.
The Siemens teleservice software takes a little "practice" getting setup and used to.
http://www.sixnetio.com/htmlhelps/catalog/5a6d7a7.htm

I have made dozens of installations with TeleService connection.

One thing I found out at first installations was that ALL MODEMS DOESN'T WORK WITH TS-ADAPTER.

I think it was Telewell modem that I didn't get working, but there must be some others too. Maybe they work by changing some AT commands?

I have used ELSA MICROLINK and it works perfectly with default settings in modem and TS-adapter.

Best regards,

TS

Tom,

some years agoo, when we were designing a telemaintenance course, we tried a modem connection to an S7-200. It seemed that S7-200 used 11-bit serial bitframing (startbit - 8 databits - paritybit - stopbit). Most modems we tested back then were only able to work with 10-bit frames. Maybe that's the same problem you're having.

Kind regards,

tesalmin said:

One thing I found out at first installations was that ALL MODEMS DOESN'T WORK WITH TS-ADAPTER.

I think it was Telewell modem that I didn't get working, but there must be some others too.

Click to expand...

The modem Tom said he is using is listed on the Siemens support site as a compatible modem, so it should work.

Tom,

I can't assist you much here as this is something that I have never done, but if you go to the Siemens Support Site and enter 9821946 in the search box, this will take you to a FAQ that has the error message you describe, although not for the modem you are using. It might help you though.

When you get it working (which I am sure you will) can you post your findings here.

Paul

Thanks to all for the help.

Rolf, we tried the changes you suggested on the modem, with no success. We have a Sixnet on order and will try that. I'll lwt you know what we find.

Success

We got the Sixnet modem in, and Tim had it up and talking in 5 minutes. Thank you to all for your help.

I did find out that Westermo has a SPECIAL modem (at a special price) for use with the Siemens PLCs, apparently as a result of problems with the standard unit.

We finally got a response from Siemens tech support - the support guy that responded didn't have any answers, but he DID know the extension of the guy that might have answers, and when THAT GUY would be back in the office (which is apparently not yet!)

We couldn't have done it without your help, guys!

Tom Jenkins, COF