Applies To:
  • CitectSCADA 5.xx, 6.xx
  • CitectHMI 5.xx, 6.xx

Using the UNITE driver to a Schneider Premium TSX P572634 PLC across Ethernet, CitectSCADA will not read any I/O data addresses (i.e. %Ix.x.x, %Qx.x.x), even though they are given as valid data types in the protocol help.

Error code 0x105 is being return as well as "Bad User Parameters" being reported by the kernel whenever I/O tag is read.

The Unity Platform PLC has a limited implementation of the UNITE driver. The Unity Processor will not respond to a read /write requests to Input and Output words/bits. The processor has implemented read / write opcodes for internal bits and not for the I/O words/bits.

As a workaround if you want to read and write to Input and Output words/bits, it is recommended that you implement address mapping within the PLC code. 

UNITE, Premium, IO