PCM301 comms issue

[Blackadder77]

Hello, I'm hoping someone can help me please.

We have a PCM301 card that has stopped working for some reason on a 90-30 PLC (possibly due to a duff battery which has been replaced). It is being used to do some maths and move the results to some analog outputs. I have a megabasic program for it but when using the PCOP software on a windows laptop, I have no comms. Pressing the restart button doesn't seem to make a difference either. I'm using a 9-pin female to 25-pin male (connected to port 2 of the wye cable). I've tried various comms settings and serial cable configurations but am getting nowhere. On another thread I found a pinout that does make the US2 led on the card flash but still no comms on PCOP. The pinout I have is:

2-2
3-3
7-5
5-7
8-4
20-8

Any help would be greatly appreciated.

 

[Steve Bailey]

For PCOP connections you should be using port 1 on the PCM module.

PCOP is kind of finicky. Have you tried doing a "hard reset" of the PCM module? Hold the white reset button for more than 5 seconds. Less than 5 seconds is a "soft reset" which will restart the default program and won't do anything if you've lost that program due to a battery failure.

 

[Blackadder77]

Hi Steve,

Thanks for the reply.
I think I did try port 1 already but I'll try it again tomorrow, I'm just about to head off home. I have tried both soft and hard resets too to no avail.

 

[Steve Bailey]

What OS are you working with? The last time I tried connecting to a PCM it was with DOSbox on a Windows XP machine which had a real serial port. That PC has since given up the ghost but I've not needed to try a connection using anything newer or with a USB/serial converter.

 

[Blackadder77]

After changing the cable over to port 1, now I have the US1 led flashing every 6 seconds or so but still no comms.

The laptop i'm currently using has Windows XP with a real serial port. I have also tried a Windows 7 laptop with a serial to USB converter.

 

[Steve Bailey]

The flashing LED indicates traffic on the port. If it started flashing when you plugged something into it, that indicates whatever you plugged in is the source of the traffic. A brief flash every six seconds indicates the sender isn't getting a response, or not the expected response. That's usually due to a mismatch of port settings.

 

[Blackadder77]

On the edit configuration data menu, F6 "edit serial port config for ports 1 & 2", this is the only place I can see to change port settings and they are the same as the com1 port settings in device manager. The megabasic config is set to use com1 but I just noticed an advanced config menu where there's "edit programmer comms" settings. These are set to NULL for programmer comms data so is there anything I need to change there?

 

[Steve Bailey]

That should probably be COM1.

 

[Blackadder77]

As I don't seem to be getting anywhere with the connection issue, the other option is looking at the .PGM file to see if I can replicate it in the ladder logic instead. Does anyone know what software I can use to view the .PGM file please? I've searched the internet without finding anything that works so far. The best I can find just opened it up like a notepad file which, apart from a few lines, didn't make any sense to me.