BMXNOM0200 READ_VAR

[YONGHO-KIM]

I am using BOMXNOM0200 card for RS-485 communication.

1) PLC : Modbus RTU (Master)

2) Device : Modbus RTU (Slave)
- ch0 : rs485 (2w)
- ch1 : rs485 (2w)

There is no problem when there is normal slave communication with CH0 and CH1.

However, if communication failure occurs in CH1, the communication value of CH0 will not be updated.

The reverse is also true,
If a communication failure occurs on CH0, the communication value of CH1 will not be updated either.

If you have any suggestions or suspicions on the cause and solution of this issue, please share them with us.

[YONGHO-KIM · Accepted solution]

I am attaching the contents related to the issue and solution as attached file.
Please refer to it for your work.

[RagulgandhiGopalakrishnan]

Can anyone please share the example program for read_Var for Modbus RTU in channel0 and channel1. i have 2 different slaves in channel 0 and channel 1 for me channel 1 is working i received the data but channel 0 i am not received any data it shows the error 16#0100 i tried the above pdf but its nit work for me.

[YONGHO-KIM]

1. Please capture and upload your current Read_VAR settings.

2. Check the CH number and Slave ID as shown in the capture below.

3. Refer to the YouTube video below.

https://youtu.be/D5R5Tc_9PP8?si=SaNQXAUkn7dymcuU