Hi, Not long ago, I used the Modbus_RTU_7 library downloaded from the PLCnext Store. I was able to successfully interface a RTU device on a 2019.0 environment. Recently, I migrated to the 2020.0.1 environment so I had to upgrade to the Modbus_RTU_9 library. I was very satisfied to see the library improvements. I first started by looking at the MB_RTU_9_EXA_AXL_MA.pcwex demo project.
I just added an extra axioline device (AXL F DI8/1 DO8/1 1H) and also added a MB_RTU_FC4_4 block and then transfered my program successfully to the PLCnext (all LED indicators just fine). But the read request failed all the time with the same error code: wDiagCode: 16#C020 & wAddDiagCode: 16#0010 “Timeout when sending”.
Using a terminal console I was able to confirm that nothing were actually transfered.
I verified every aspect of the program and was unable to find anything wrong. I am 100% sure abot the hardware setup. I downgraded the PLCnext to 2019.9 to use my previous project with its Modbus_RTU_7 library and everything went fine. The same terminal console showed me the expected transmission. Can you give me some hint about the “Timeout when sending” error ? Can you test this demo with the same configuration than mine ? PLCnext AXL F 2152 + AXL F DI8/1 DO8/1 1H + AXL F RS UNI 1H PLCnext Firmware : 2020.0.1
PLCnext Engineer: 2020.0.1
Modbus_RTU_9 library
MB_RTU_9_EXA_AXL_MA.pcwex
MB_RTU_FC4_6.xEnablePoll_FC4 = TRUE
MB_RTU_FC4_6.xMode = FALSE
serial-1: protocol = “transparent”
serial-1: Data exchange = “via process data”I would be glad to send you the complete altered demo project if you need it. Frédéric