Malformed Modbus message for Function Code = x17
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#24 Malformed Modbus message for Function Code = x17
Hi,
I've been using this software as a modbus server while developing a modbus client on a device. So far it's been working wonderfully and it's great to be able to see all the registers and addresses etc.
I am in the process of implementing FC23 (read/write multiple) and as a test I am generating the exact same frame that is used as an example in the modbus application protocol specification page 38.
On the server side with ModRSsim2 I get the following errors in the Comms:
11:20:33.680 RX:01 17 00 03 00 06
11:20:33.680 RX:00 0E 00 03 06 00
11:20:33.680 RX:00 0E 00 03 06 00
11:20:33:680 Malformed Modbus Message for Function Code = x17
11:20:33:681 RX:FF 00 FF 00 FF 46
11:20:33.784 RX:91
11:20:34.298 Timeout on Message Receive. Dumping Data.
From what I can see, ModRSsim2 receives exactly the right bytes to form a valid FC23 request. I've also run that output through several modbus parsers and they all state that the frame is a valid request.
I have had no problem with any of the other function codes I've tested so far (3, 4, 6, 16, 22).
I am running version 8.21.2.7 of the software.
FYI- I think no one is listening...
Sorry for the delay. I have had health problems lately and am moving slowly these days.
From looking at what you attached, it looks like you may be testing using the "serial" protocol.
If so, then I have not addressed this at all. I have been testing and using only the TCP/IP protocol.
FC23 was the last Function Code that I added and did not address the "serial" side.
I retired about 2 years ago and no longer use this much, so there is not much chance I will fix this.
Thanks for reporting and if I do decide to work on this in the future, I will try and address this.
I've fixed this here
https://github.com/Cavaler/ModRSsim2/releases/tag/v8.22.0.1
Jonas, As I mentioned above, Function Code 23 was not implemented on the Serial side. I plan to post an updated versions of this program within the next month that will implement it in version 8.21.2.8, so maybe you can watch for it. I have just recently found time to address this issue.
Pavel, Your fix just removed the error message, but did not account for the needed response. Thanks for forking and working on this.
Doug Lyons
Hi Doug,
While I haven't been using this program for a while now, I will make sure to give it a twirl once an update lands ;-)
Jonas,
I have just uploaded a new version 8.21.2.8 what should have this functionality completely implemented for both Serial (your case) and Ethernet. Enjoy and Thanks for your interest and comments on this project.
Doug Lyons
Closing this now.