Micromod MOD: Extended Modbus (XModbus) OPC Server Users Guide - Manual (Page 36)

Extended Modbus OPC Server
Operation and Reference
Read input registers (any data type) from (31001 - 31999) (32001 - 32999) (33001 -
33999) (34001 - 34999) (35001 - 35999)
Maximum Values - 125 registers
4.2.3 Scaling
Use this menu to define the conversion of raw data into engineering units and define that
as a New Style. You may also delete any styles no longer needed.
To add a new style:
1. Select an existing style to base the new one on if available.
2. In the new style menu enter a unique name and check the initialize from box if it is to
be based on the previously selected style or leave it unchecked to use the default style
scaling data.
3. Enter the following data as appropriate.
Units
Raw Minimum value
Raw Maximum value
Scaled Units Minimum value
Scaled Units Minimum value
Conversion selection
Linear
Square Root
4.2.4 Scaling Analog Values for Commander Series Instruments
The first Commander instruments to support MODBUS handled scaling of analog
values in a different way than later instruments. The ABB C200, C300, C1900 and
PR100 instruments use a 12-bit register with a raw range of 0 to 4095. The host must
scale the value to obtain the desired engineering unit value.
Newer models, such as the ABB C100, C150, C250, C500 and PR250 instruments,
place an engineering unit value into one or two 16-bit registers. If two registers are
used, the data type is considered a long integer. Values are represented as positive or
negative integers without a decimal point. If a decimal point is used in the
instrument, additional scaling must be performed at the host.
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