MC3 APP In Problem

Kevin 9 years ago updated by Ulrik Zakariasson (Software development) 9 years ago 3

I have a problem with a system that uses APP in and out between three modules, one MD4, two MC3. I have found that one MC3 does not appear to be receiving APPIN's. When I monitor the modules in IQAN Run, all modules appear to be talking successfully. When I look at IQAN Design the APPIN's on the module that's faulting says Error, Timeout and its red not green. On the module that's sending the APPOUT, the function block APPOUT is green and OK. Its almost as if the modules are not starting at the same time and the timeout for the first APP in to be received is being reached?

Is there any way of finding out more information about this error?

The machine was working OK for some time and it just happened randomly and now im unable to recover the machine. We also have other machines running this software and same software version and it appears OK.

I have extended the 50ms cycle time to 100ms,on all three modules with no success. Is there any reason why this could have happened? Running Design 3.19.9.


The APPIN:s will get the status Timeout when there is a No contact issue.

You would most probably also see in the log of the MC3 that has APPIN timouts that it is having No contact with at least the master module that is sending the APPOUT:s.

I would also expect that you see the 3:1 blink code (3 red, one yellow) on the MC3 that has the APPIN timouts.

Normally, a local error on one master will get shown on the MD4 in the system, but in case of a No contact, this is of course impossible to send the message to the MD4.

A CAN bus wiring issue is the most probable cause.

We found the issue, there was a break in the master bus CAN A. I was confused because I could see all the modules in IQAN Run, but this runs over the diagnostic bus, CAN D.

The modules were seeing a genuine break in the CAN bus which restricted any communication between the modules on the master bus.

Thanks for the info.