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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | Re: CRC issues using Modbus/asyn on 64bit Linux |
| From: | "Martin L. Smith" <[email protected]> |
| To: | Ralph Lange <[email protected]> |
| Cc: | EPICS Tech Talk <[email protected]> |
| Date: | Thu, 01 Mar 2012 12:27:43 -0600 |
Hi Ralph, I have been running Modbus/TCP from a 64-bit Linux OS under EPICS R3.14.11 using ASYN 4-16 and Modbus 2-1 and have not noticed any issues like this. I'm using Modbus functions 1 & 4 with single 16-bit word access and read only. Would these messages show up on the IOC console? I'm not specifically looking at the CRC which is why I asked where I would see the messages at or how I would be able to see them would probably be a better question. I'm not certain that my device supports CRC either. Marty Ralph Lange wrote:
Hi, I am reliably getting CRC errors on the device's answer when reading more than two parameters (Modbus code 3) through serial RTU on RS-485 from a Wave P6100 temperature controller. The data itself looks good and reasonable. One or two word access (Modbus code 1 or 3) seems to work fine. The IOC runs on 64bit Linux, using Mark Rivers' Modbus on ASYN driver. (All from synApps 5.5) Has anyone seen similar behaviour? Does anyone successfully run Modbus/asyn on 64bit Linux? (To rule out 64 bit issues in the CRC checking part.) Thanks for any help, ~Ralph