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Answered

MD4 reporting MC2 VREF error high 6.60v

GPARRY 4 years ago in Master modules / MC2 • updated by Gustav Widén (System support) 4 years ago 2
Hello,



I’m experiencing a MC2 VREF error high 6.60v show up on a MD4 display unfortunately the product is not currently here to troubleshoot but I would like to know if this may or may not be an already known Bug with master to master communication/hardware monitoring. In the MC2 I am not using the module diagnostics for VREF, however assuming it still reports that information to the headmaster.



This is on a 12v system and the only place the 5 volts is used is 7 switches (on/off) as a checksum/and direction change sense to high impedance analog inputs. I have done this before without issue however it was 2.6 software, this is the first one with 3.0 software.



I thought seeing as I can’t troubleshoot it at the moment I would ask and possibly save time if this already a known issue.
Under review
Correct, a local fault on the IQAN-MC2 will be reported to the IQAN-MD4 even it the MDGN for MC2 VREF has not been added to the application.
There are no known bugs related to the reporting of module diagnostic faults.

From the MD4 menu system, you should be able to go into the MC2 log and see when the VREF error occured. You can also go in and check the measured value on the MC2 VREF via Info-Modules. (on the current version of sofware, the MD4 only gets the value from the MC2 when you enter the module info page)

I would guess that the MC2 VREF has been shorted to some other signal. I think that the VREF has an upper limit on the voltage it is reporting, even if it is shorted to a higher voltage. I'll check what that level is.
Answered
I checked, the maximum voltage that the MC2 VREF is can measure is 6.6V.
If it is shorted to a voltage above 6.6V, it will still report 6.6 in the VREF error. In this case, I suspect that the VREF has been shorted to the 12 V.