Modbus RTU stop working in SL

[jose_dli]

Hello, 

SL has not been responding to modbus messages for a few days now. In the installation there are 4 Energy meter EM112 and a heat pump, for each of them I get the following error: "device1 (RTU 1 slave xx) read failed: Operation timed out"

This installation was working perfertly 3 years, but from one day at 00:00. All the devices stop their comunications. I review the cable (A, B and Ground) and final resitances, they are in right ohm. Also modbus message parameters on every device (baud rate, parity... ) was checked. 

Also, I tried to increase timeout, and comunicate directly to a well know coil by tool "Read test" and lua script, with no luck.

Any help or hints would be welcome. 

Regards,

[Daniel]

It sound like something has been damaged. In LM we can check RS485 by connection it to second but you have only one.
Did you try to connect just one slave?

[jose_dli]

Yes, I rewire from SL to the nearest meter, and tried with the tool "read test" but it doesn't work. I can't check if the device damage is SL or meter. 

Is there any way to check if the port RS485 is broken in the SL?. And SL works with any chip RS485 usb external?

Thanks for your help,

[admin]

All common USB-UART chips that are used in 232/485 adapters are supported.