Profibus Diagnostics Question


Thread Starter

Joe Mc Donald

Hi there,

On a profibus DP installation I am planning to run at 12mbs. Is there a way that I can automatically detect (maybe on a scada screen) if the baud rate drops below the desired rate.

Note: I am using a Siemens S7 PLC with Profibus comms card connected to the field. Ideally I would like to be able to show graphally (on a scada screen) this drop in rate, so that the operators of the plant can inform maintainance personnel.

Any ideas welcome!!!!!!!

Thanks a 'mill in advance.

Joe Mc D
Use the Siemens Diagnostic Repeater, this provides data as to the health of your Profibus Network.

James Ingraham

You'd have to ask Siemens if that data is already available in their system.

An alternative is to put a Profibs slave card in a PLC that is talking to your SCADA or in the SCADA system itself. The Profibus Multi-slave card from SST ("": , part# 5136-PBMS-ISA) or the Profibus slave card from Synergetic ("": , part# SMS-CIF30-DPS). I believe they auto-sense baud rate and can report it.

-James Ingraham
Sage Automation, Inc.
The speed is given by the master and this
is done by DP master configuration

it will never change !!

the slave just adapt automatically to the master

Donald Pittendrigh

Hi All

What makes you think the baud rate will drop? If the master is programmed to run at 12M this is what it will do until the target rotation time is exceeded at which time, as far as I know, there is no way to reduce the baud rate and the bus will fail.

D.C. Pittendrigh