07-07-2005 12:02 AM
07-07-2005 01:03 PM
07-07-2005 11:32 PM
Beth,
Thanks for your reply.
I have verified the settings for the serial port and the settings in the controller. They match well. I dont think the serial port configuration parameters are a problem, but the convertor or the wiring could be !
I am using the Black Box RS232 to 485/422 convertor. I am not sure this is going to be working with Honeywell controller. What type of converter did you use ?.
07-08-2005 07:30 AM
J.A.C.
Darn, I was hoping it was just serial parameters that didn't match up - that's usually my problem.
As a matter of fact, my predecessor used the RS232/485 converter from Black Box, so it will work if all the settings line up. (He used lookout, so I assume it was just the Modbus driver object, not a special Honeywell driver) I had to convert from RS485 to Ethernet, so that config doesn't really apply though.
There are a lot of jumpers and settings in the converter.... If it were me, I would start messing around with some of them, like changing to half duplex, adding some delays. I found the manual, and it seems to have a loopback test built in, I don't really know if this would help you eliminate the issue as being on the 232 side.
If it helps at all, here are some of the settings I used in the Honeywell:
ComSTATE=Modbus, SHED ENAB=ENABL, SHEDTIME=1, BAUD=19200, DUPLEX=HALF, WS FLOAT=FP B, TX DELAY=2
Everything else was still the factory default I think. I honestly don't know what the SHED settings mean, or why they work, just something else to try.
Best of Luck!
Beth
07-08-2005 08:55 AM
07-08-2005 09:50 AM
I hope someone else has more experience with this particular application, I wish I could help more. Keep trying though, these devices should be compatible.
To answer your other question, we have been converting some of our serial device outputs to ethernet so they can be logged to one central computer located anywhere in the plant. I've got a converter that formats serial data into TCP/IP packets, then back into serial on the PC, so your computer thinks each serial device is hooked up directly to another COM port. (I used to wonder why they listed hundreds but I could only use COM1, now it makes sense!) It's pretty nifty, but doesn't really apply for what you're doing.
Good Luck! I'll let you know if I think of anything else to try.
07-11-2005 01:59 AM
07-13-2005 11:12 AM
07-13-2005 11:33 PM
07-27-2005 10:11 AM
Hi,
I have been having intermittent problems using modbus through the IA OPC Server, so I would like to try the honeywell VISA driver mentioned above. I am getting the same message of "Communication Failure. No response from the controller."
The hardware setup seems fine since I can establish comms using the IAOPC. Are there any settings that need to be changed in the honeywell controller or in the VI in order for it to communicate properly? Just fishing for suggestions.
Thanks,
Beth