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plcguy76 March 23rd, 2009 10:05 PM

AB INVIEW Display From Modicon Quantum
First post here, but I will try to be thorough.
I am trying to display alarm messages and variable data from a Modicon Quantum PLC. We had a 2 line ASCII display that quit working, and apparently nobody makes a replacement. We are trying an AB INVIEW 2706-P22R display. Communication is serial RS232. All messages are pre-programmed in the INVIEW, and triggered by an ASCII string from the Quantum.
We are using a Gould J892 2 port ASCII module in a Modicon 984 rack, as a remote rack to the Quantum PLC. We have confirmed using Hyperterminal that the proper ASCII string (^T1^M) is being sent to the INVIEW, and cabling appears to be correct as we can trigger a message using the INVIEW software across the cable. There is no COMM light on the INVIEW to indicate if communications are working. All tech-support(AB and Modicon) insist everything should be working.
Any help would be greatly appreciated.

Ken Roach March 23rd, 2009 10:55 PM

I'd focus on verifying the serial data.

Try hooking up the InView software to a PC running Hyperterminal (or better yet, Realterm) and attempting to trigger a message. This will show you for sure what works to trigger a message.

It's often also helpful to put a "breakout box" on the RS-232 line to provide a visual indication of when data gets transmitted.

Are you using the same cable for Modicon -> InView as you are using for Modicon -> PC and for PC -> InView ?

Ken Roach March 23rd, 2009 11:06 PM

Gonna have to talk this one out
We know that your PC has a "DTE" type RS-232 port.
We know that the InView has a "DTE" type RS-232 port.

If the PC -> InView cable works, then it is a Null Modem type cable.

If the Modicon -> PC cable is the same cable, and the PC sees data from the Modicon, then we know the Modicon is DTE as well.

Therefore the Modicon -> InView connection is DTE ->DTE and can use the same null modem cable.

plcguy76 March 23rd, 2009 11:13 PM

The cabling gets quite complicated as the ASCII card has a DB25 connector on it, so when we trigger a message with INVIEW software from our laptop, we have to use a DB9 to DB25 convertor. Also, when we put our laptop at the INVIEW end to test with Hyperterminal, we have to use another cable to switch from DB9 female(INVIEW) to DB9 male(Laptop).

Ken Roach March 23rd, 2009 11:24 PM

Yeah, I have a deep box full of those kind of converters.

DB25/DB9 converters and "gender benders" almost never also act as null-modem adapters.

Take one little step back; you do understand that the "Control-T" is a one-byte control code, hex value 0x14, not a two character "^T", right ? And the "Control-M" is one byte, 0x0D, for a carriage return.

Hyperterminal has a mode that I recently discovered where you can make control codes displayable. Change the Font to "Terminal_Ctrl+Hex" to show the control codes.

plcguy76 March 23rd, 2009 11:29 PM

That sounds a little "Greek", but I think I understand what you are saying. We are using Proworx 32 on the Modicon, and when we are programming the ASCII message in the editor we have been using "Shift 6", "Shift T" to get the ^T, but it sounds like you are saying that is not right. We questioned Modicon tech support and they said that as how to do it.

plcguy76 March 23rd, 2009 11:36 PM

We have also hooked up Hyperterminal when triggering a message with the INVIEW software, and we get a very long string with black happy faces, and white happy faces. Not sure how to program those!!

Roy Matson March 24th, 2009 01:51 PM

""We have also hooked up Hyperterminal when triggering a message with the INVIEW software, and we get a very long string with black happy faces, and white happy faces. Not sure how to program those!!""
That's typically what you see if your port settings dont match. Slow the daud rate right down say 1200, try different combinations of parity etc. Once the string makes sense then you can speed it up again.
You can tie your laptop in parallel to monitor the communications, I use an old cable, cut off one end and connect Rx and Gnd into the shell of one of the connectors. You can also monitor RS-422 that way connecting to the negative wire and Gnd


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