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• Chapter Six - Advanced Options DDE Server User’s Guide
Adding a Register Group
Click this button to add a new register group. The Select Register Group Type
dialog box appears:
Enter the Register Group name. The name may be up to 20 alphanumeric characters
and cannot include embedded spaces or special characters, such as: + * / /, ? () “ ‘.
Select the register type from the Select Register Type pull-down list. The Modbus
Register Types shown are determined by the function codes selected previously. The
four types of register groups that support some of the Modbus function codes are R0,
R1, R3, R4. The table below describes the types, registers, supported codes, and
uses.
Type
Code
Type of Register Supported
Function Codes Use
R0 Coils 01 Reading coil status
R0 Coils 05 Setting/forcing/
executing coils
R0 Coils 15 Setting/forcing
multiple coils
R1 Contacts or discrete
inputs
02 Reading
contact/discrete
inputs
R3 Actual value or input
register
04 Reading actual value
or input registers
R4 Setpoint or holding
register
03 Reading setpoint or
holding registers
R4 Setpoint or holding
register
06 Presetting single
setpoint register
R4 Setpoint or holding
register
16 Presetting multiple
registers
You will need the device’s Modbus RTU protocol specification for the correct codes
to add or delete.
Click OK to accept your new register group – the Register Group dialog box is
displayed for you to finish defining the characteristics of the new register group.
