HC900 interface to Honeywell DCS TPS -HPM SIO module


HC900 variables andsignal tags, including digitals, are represented as 32 bit FP data values. The HPM-SIO module requires the use of 70000-79999 address range in the SIO when requesting FP data from the fixed HC900 modbus address map 6337- 7535 for variables, 8193 thru 9999 for signal tags.

The SIO module does not support six digit Modbus addressing, so it is not able to read HC900 addresses above 9999.
Using the Custom Modbus Mapping option in the HC900 (after V 4.0) will allow the user to re-map the register table of the HC900 to provide more addresses within the range supported by the SIO module. Additionally, the user can define the data type of the register as FP (as above) or Interger to provide SIO access via 40000-49999 address range.

Lastly, using the Digital Encoder function block within the HC900, sixteen digital signals (Flags) can be packed into a single register to provide a bit packed register to the SIO module. The signal tag applied to the output of the Dig encoder block, must be defined in the Modbus Map as an Integer.