Dear All,

There is a system, 317-2PN/DP installed with 5 IM151 nodes

4 are ok but 1 is showing SF/BF. I have checked online hardware configuration, node 15 showing a forward slash on it

checked diagnostic buffer, showing IW30 and PQW188 read/write error

IW30 is first DI module and PQW188 is first AQ module. checked by replacing these but the fault is same

is there any way to trace the exact faulty module as it is difficult to replace modules without knowing how many and which are faulty

waiting

Hello Shelbi;

I suggest you allow us to look at the full contents of the CPU's diagnostic buffer, as an initial step.

Open the diagnostic buffer snd use the button marked "Save As.." in thr buffer screen. This will generate a text file containg all the diagnostic messages logged in the buffer and other information that could help understanding the source of the problem.

Attach the text file to uour next post in this thread so we may examine it.

Hope this helps, 

Daniel Chartier 

diagnostic buffer is attached

fist is PM-E

slot 2-9, DO modules address 30.0-33.7

slot 10-17, DI modules address 30.0-33.7

slot 18 PM-E

slot 19-22, AO modules address 186-201

Please suggest how to find the exact faulty module in this arrangement

One more thing I want to add is SF LED of both the Power modules are ON

I checked the voltages across pin 6 and 7 of the terminal block and it is showing 24V DC

Hello Shelbi;

First thing, your diagnostic buffer is set to only 10 messages, and as it is a circular buffer, the newest fault message overwrites the older ones. So we have little information to work with. I strongly suggest you open the Settings button in the diagnostic buffer page and increase the number of entries to at least 100, 500 if you can. Let the system run a few minutes and generate the text file once more. We should be able to detect trends in your fault log.

For the moment, all I can say is that your system is unable to read addresses PIW 976 to PIW984, which you do not mention in your module description. What do they connect to? Check the hardware configuration for details. Could you post a screenshot of the hardware configuration, in online mode if possible?

Hope this helps,

Daniel Chartier

There were 7 profibus encoders in this system. I backup the original PLC program, deleted the encoders from HW configuration, inserted new MMC into PLC slot and download the edited program into new MMC

addresses 976,978.... were of those encoders

I checked cross reference but there is not such addresses there

can you please tell me how to find out these addresses