Applies To:
  • CitectSCADA
  • CitectHMI

I have problem writing a LONG value to the MW5001 register using the UNITE protocol. 

The MW Citect data format (address) is only valid for an INTEGER.

To write a LONG value, we need to use the MDW Citect data format.

The address MDW5001 is invalid and will cause a compile error "Bad iodevice variable". This is because the driver specification indicates that the address must be on an even address boundary.

So therefore the correct addresses to use are MDW5000, MDW5002, etc.

TIP: An enhancement request have be submitted at the time of writing to also support odd addressing for the MDW so this may be valid in the future. Please check the UNITE Driver Specification.