Profibus PXI Card doesnt work properly as Slave. Previously was used as master.

[Opalka]

Hi all,

normally I am using profibus card as a Slave (Siemens Sinumeric device is the Master). At the beginning the communication worked properly without any problems.

After that I used profibus card as a Master (some sensors were Slaves). Again the communication worked properly without any problems.
 
And after that I used profibus card again as a Slave, with the same device and with the original project. Master can read my frames without any problems, but Slave does not accept anything. After the communication estabilishment the Master switches to Clear mode immediately. I used another Master device and there was the same problem.

Is it possible to set profibus card to factory setting or something like that? Can be reason of this problem, that profibus card was used as Master before (the card was configured by the Comsoft Configurator II software)? Is it possible to clear Master configuration from the profibus card?

The address, baud rate and slave module are set correctly.
The Profibus Card is from Comsoft (NI PXI-PROFIBUS Interface 780161-01).

Thank you in advance for your answer.
Jan O.

[Jesse_D]

Hi Jan, 

Writing frames out as a slave should switch the card from master to slave mode. However if you haven't re-initialized the card in slave mode it will not leave master mode. 

Aside from that you might run the slave shipping example and look at the "Monitor/Modify" and "Status Info" tabs to see if any error is being thrown on the card. 

[Opalka]

Hi Jessi Denis, thank you for your answer...

I actually initialized the card into the slave mode using the VI (see below).

I tryed to run slave shipping example and as I wrote at beginning, master is in clear mode (bit 1 of status byte is active). Slave is in data exchange mode (bit 7 is active). There were no errors.

Master (Siemens device) can read frames from slave and slave (profibus card) does not read anything. There is the question, why the Master automaticly switches into the Clear mode. Firstly I thought that there is something wrong with Siemens device, but I tried to use two different Siemens devices and the behaviour was the same.

I used the original projects (in Siemens and in LV) which worked properly before I used the profibus card as Master.

[Jesse_D]

Hi Jan, 

Thanks for the clarification. 

When I use this card I didn't have to do anything to switch it from master to slave except use the API. The status bit you are looking at should be set by the master as a sort of safe mode. 

The manual (for the c-RIO module, but has the same status bit), indicates that this should be something that is cleared on the master. 

Alternately, it is possible you might have found a bug. My first thought on a work-around is to re-download a configuration from the Configurator with no slaves. After that try using the slave initialization again. 

Finally, there is a reset states option on the slave API that you might try.