cognex to 984 plc

[Rdsbird 1]

I was thrown into this one. I have a 984-785e plc and they are trying to read bar codes into the plc using a cognex 5100 vision system w/cio1450 module(serial rs 232c).They have a cm-42 interface module(Datalink). Got the cm-42 on MB+ to talk using MSTR. Problem ,no data from camera in buffers after read. IS there an easier way to make this work. We can not be the first to interface a cognex to a 984 plc

[Modiconbob 2]

You have quite the "cluster" there! I'm not familier with any of the equipment other than the Modicon 785E, but I see no reason why it shouldn't work. That is assuming all is set up correctly. Sounds like you are converting a "read" MSTR command on MB+ to RS-232 via one "box" and then reading the vision system. First, I'd place a dumb terminal type device where the vision system is connected to see if indeeed you are getting a read command converted to the RS-232 port. I'm pretty sure that's where you'll find that you're in trouble.

[Rdsbird 1]

Thanks for the cluster remark,you are correct, it is. Just to let you know it was all of the stuff. Did dumb term, and found camera not set up right. Did wiring check ,bad wiring,fixed. AND my bad in that the MSTR was to send the command to recieve but I didnot take overhead into account. Got it to work ,but-t-t-t-t- ther has to be a better way to get 2D bar codes into a 984 plc.

[Modiconbob 2]

Well I'm glad that you got it all to work! The only other ways to get the info into a 984 are through a ASCII port (rs-232) on a remote I/O interface like a J890/P890. This can be a little cumbersome when using the acsii read/write blocks in ladder logic though. It would however eliminate the need to convert from MB+ to rs-232 though. Not sure if the hassle of the additional programming would be worth it. Another way is, I believe there is an after market 800 series card that takes in bar code data and puts it right on the I/O bus to be retrieved. I don't recall who makes it. Maybe Data Logic? Good luck!

[Rdsbird 1]

The cm-42 is from data logics. The engineer I talked to didn't have a clue because this module has not been sold for several years.The buy out by EMS hurt my chances of getting help.Sorry that i said data link. The maddening project got to me.The boss knew this was a bad one thats why he always gives mme the winners that most people run from. BY the way It lasted only overnight ,cycle power and the cm-42 refused to give up its information. Had to reprogram module .Wonder if this is normal for this module.

[Modiconbob 2]

Can't answer that one, I have never used that particular unit. I used to work for Modicon and I know one of my old application engineer buddies that is still there, and he may could help you more. Email me directly and I'll give you his number. bobculley@deltaautomation.com

[Rdsbird 1]

Sorry I did not answer back earlier.Found out the cm-42 modbus plus interface modules are not that bad as I first thought.Worked out pretty nice.A few MSTR instructions and some logic got good results. A tip if anyone uses these; put the 24 volt supply above crm. This was the ploblem. They hit e-stop ,lose power to cm-42, it loses program.The customer would not budge on this ,so i wrote a start up routine when crm come on ,I download the program back in . For all I went through , for an older 984 system , I would use the cm-42 again and thanks for all your feedback.