Profibus DP problem

I have a 3rd party profibus device that I can't get connected to my DP network. I have sent the unit back to the manufacturer who have tested it and say it works with their DP system OK. I have 4 other devices on the network, an IM151 with a DP master module, 2 Simocode pro Vs and a TP177B. The network is configured as DP at 1.5 Mbs. The cabling is ok as I have connected it to one of the Simocodes and that works OK. Anyone got any suggestions as to why this won't work as I am getting batted about between the 3rd party manufacturer and Seimens. The units are all fitted into one panel.

[joke on]

As its siemens have you tried the BIG hammer approach ?

[joke off]

Hi John,

Is there a GSD File for the third Party Device? Usually you have to import it into the hardware file of the project, then add it to your DP Network & Download to the Controller.

Hope this is some help to you.

John

I would point the question to Siemens. In any DP system, the slaves can only do what the master tells them. And as Siemens supply the master in this case they control all the network activity. Of course if they prove it works, expect a bill!

Is the slave a certified DP slave by the Profibus Organisation? If so, I'd be extremely surpised that a certified master and certified slave won't work together.

When you say you can't get it connected, what are the symptoms? And what tests have you done so far - terminating resistors, cable lengths, hardware configuration, etc?

regards

Ken

John,

reading Ken M's post brings one other thing to mind, You can go online in the hardware configuration and see if anything stands out as a potential problem. There are also FB's, FC's & SFC's which may aid in the diagnosis, ie FB125,FC125 SFC51 etc

Regards

STL

Hello John:

I have a 3rd party profibus device that I can't get connected to my DP network.

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If that is the only info you are going to give us you can't really expect us to help you much, can you.
I have worked with Profibus for a few years, and connection problems I have encountered come generally from 2 areas: mistakes in configuration (gsd file integration, bus speed and parameters, addressing) or in wiring (misconnection of the shield in the connectors, inversion of A and B lines at a slave). I can assure you that all Profibus slaves, if they are certified, will respond at least with a diagnostic messageif correctly set-up.
Please decribe:
-the type of master
-the type of slave and addresses you have set up
-what configuration software and setup you have used
-symptoms of what you mean by "can't get connected"
-master diagnostics you have done (system LEDs, diagnostic buffer...)
-slave diagnostics available (LEDs, messages...) that you have checked

With at least a part of this information we can give you a hand.

Hope this helps,
Daniel Chartier

All of the above , and of course make sure that you turned off the term resistor at the last original device .It happens !

My simple approach would be:

1. On the master CPU I would connect my PC and use the diagnostic feature in the Set PG/PC Interface utility. You can then see if the DP slave is there or not, or if it appears at the wrong address.
(This is only possible with a CP5511 or CP5611, not with a PC adapter. The PC adapter does not have the diagnostics feature).

2. If the DP slave doesnt appear at all in the above diagnostics, then I would disconnect the Profibus cable from the DP slave and connect directly with the PC, and then attempt the diagnostics once more.
If the slave appears, then it looks like a cable problem.

3. If the DP slave does appear in the Profibus network at the proper address (from step 1 or step 2) but the master still cannot connect to it, then it looks like a configuration problem. Use the Hardware diagnostics in STEP7 via the CPU as previously suggested.

Thank guys for all your suggestions, i have already tried most of them I think.

I now have rigged up a test system which is the device (a Pulsar Black Box) and a S7 315 2DP.

I am using the manufacturers GSD file.

I am using a PC adaptor, I cannot connect to the black box without the S7-300 becuase of getting power for the PC adaptor.

The network diagnostics say "cannot connect to device over the bus".

The bus fault LED on the S7-315 flashes.

If I leave the device connected but remove it from the network configuration then the BF LED goes out. (I believe the flashing LED is indication of an address read failure).

I really am at a loss here.

John,


Just a thought, does the black box state Profibus DP comms or just Profibus comms?

Change your network settings to 'standard' and try again, I would even be tempted to try DP/FMS.

Paul

Should be the other way around - if you have any unconfigured device on the network , then there should be a bus fault -

Do one thing , check to make sure this thing can run at the profibus speed that the network is configured to . This may be why the device is preventing comms when configured .

Here is another stab in the dark. Double check the node addressing, and make sure one isnt octal and the other in decimal. What node addresses are you using? if you are using 7 and under then this shouldnt be a problem.

JohnW said:

I am using a PC adaptor, I cannot connect to the black box without the S7-300 becuase of getting power for the PC adaptor.

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With a PC adapter you cannot do any direct diagnostics anyway.

JohnW said:

The network diagnostics say "cannot connect to device over the bus".

The bus fault LED on the S7-315 flashes.

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It cannot "see" any node at all on the specified address.
What cable do you have ?
How did you specify the node address of the black box thingy ?

JohnW said:

If I leave the device connected but remove it from the network configuration then the BF LED goes out. (I believe the flashing LED is indication of an address read failure).

Click to expand...

Nothing surprising there.

10baseT said:

Should be the other way around - if you have any unconfigured device on the network , then there should be a bus fault -

Click to expand...

No. A node that is not included in the configuration, may not cause a bus fault as long as the token rotation time isnt exceeded. A DP slave that cannot connect to its master will not add to the token rotation time.

I am connected using approved profibus DP cable the blackbox address is 6 and I cannot see it using "accessible nodes" in Step 7.I have tried all of the various DP, Standard and DP/FMS profiles and Baud rates of 1.5 mbs and 19,200. Still no joy. Have used the same cable to connect to other devices and they are all OK. Siemens technical support came through and talked me through my set up and couldn't find anythng wrong at all. The ball is back with the manufacturer now

As you describe it, it does sound like a problem with the slave.

How do you set the station address of the slave ?