BF LED of T760 blinks, bad commuication on the Profibus Network

FAQ #100010

Bad Profibus communication related to a to short watchdog timeout on the T760


In some cases the Profibus communication doesn’t work correctly. The BF LED of the T760 blinks and on the Profibus Master device the Profibus Diagnostic Flags are set to high to indicate a communication error on the network.

To solve the problem you have to increase the watchdog time of the T760 in the Profibus configurator.
The watchdog time is depending from the baud rate, number of devices and Profibus timing parameters.

With PG5 1.3 the watchdog time is calculated automatically and set to the correct value.
With PG5 < 1.3 you have to set the watchdog time manually by double clicking the bus line on the PG5 Profibus configurator.
In the folder "advanced" you have to write the "slave default watchdog" time in the specific field and to click the button "Set watchdog to slaves"  to copy the new value to each slave.
A value 20 (x 10 ms) should be ok for most cases. 

Re-Build and download the project.



PCD3 / T760

Last update: 30.05.2015 14:49

First release: 21.05.2004 13:26

Views: 33159

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