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Modbus error
#1
Hi everyone,

I'm trying to integrate in my LogicMachine a RDC-38 Chint network analyzer. I made myself the .json file and I think there is no problem with it but I'm getting this error in my error log:

RDC-38 (RTU 1 slave 1) read failed: Operation timed out

What could be the problem?

I attach the .json file and the modbus register manual of the RDC-38 in case you see any problem with it.

Thanks in advance,

YP

   
   
   
   

Attached Files
.json   RDC-38.json (Size: 1.2 KB / Downloads: 6)
.pdf   Communication Protocol MODBUS-RTU EMM-h IM150-U v0.95.pdf (Size: 121.05 KB / Downloads: 11)
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#2
Try using RTU read test to see what settings will work. It could be that you need to shift the addresses by -1. Datatype is most likely uint32
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#3
I made his changes and I'm still getting the same error.
I try the RTU read test and it always shows the same message: "Error, operation timed out"
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#4
Physical connection might not be correct. Check A/B: sometimes they are marked incorrectly and have to be swapped. Check if GND is connected between LM and ModBus device because it might not work without it in some cases. Another thing to check is correct baud rate, parity/stop bits and slave address.
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#5
This means that you are not connected. Check the cables and if RTU settings are correct. No point to waste time on profile till you at last get some value via RTU read test.
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#6
Good morning,

I've check the fisical connection and RTU settings and everything seems to be ok. Any other ideas??

Thanks a lot
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#7
Did you try that? This is from the slave manuals.
TROUBLESHOOTING If response from RMC doesn’t happen:
- check connection from RMC and RS232/RS485 converter ;
- check if data outgoing from the RS232 serial port of the PC come in the RS232/485 converter - try to increase the wait time for response ( 300 mS is good);
- check if the transmitted data stream is EXACTLY as in example, monitoring the data on the RS485 serial line with a terminal (i.e. Hyperterminal or other emulator);
- if the RS232/485 converter is not our model EMI-1, be sure the turnaround-time is set in range 1 to 2 mS
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#8
(11.03.2020, 07:57)programacion2 Wrote: Good morning,

I've check the fisical connection and RTU settings and everything seems to be ok. Any other ideas??

Thanks a lot

Have you set a termination resistor ? If not, you can check that.

If Yes, check if the products do not have already his own inside
Hubert FEBRAUD
Home automation integrator
Connectibat, Nantes, France
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