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Modbus RTU Slave Input Register Limitations (Modbus_RTU_12 Library, MB_AXL_SE_RS485_Slave_3)

sammsamm
in PLCnext Engineer

Hi all,

Is there a limitation with using the Modbus_RTU_12 library to implement a Modbus RTU Slave using block MB_AXL_SE_RS485_Slave_3 that you are limited to Input registers with addresses between 2000 and 2009? I would like to use just 2 Input registers, addressed 30003 and 30004, but with using this block it only seems that I can use addresses 32000-32999.

I have a device (fuel management system) that is connected to my AXC F 2152 via a AXL SE RS485 card, which has the following settings that cannot be changed:

  • Baud rate: 9600
  • Data bits: 8
  • Parity: None
  • Stop bits: 1
  • Sends a command to read the input register once every couple of seconds (slave id 01, function code 04, start register 02, number of registers 02)

Any help would be much appreciated!

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