Modbus Master
Mapping Table
Click Add Entry and specify the following mapping parameters:
•
Local Register
—Enter the starting onboard I/O register number that the specified
Modbus Master transaction will transfer I/O to/from, depending on whether it is a
read or a write mapping.
•
I/O count
—Specify the number of consecutive I/O register that will be
transferred in the mapping.
•
Function Code
—Modbus function code used for the transaction. Standard
function codes are:
•
01: Read Coil
—Read from a Coil (Output) register.
•
02: Read Discretes
—Read from a Discrete Input register.
•
03: Read Registers
—Read from an Analog Output register.
•
04: Read Inputs
—Read from an Analog Input register.
•
15: Write Coils
—Write to a Coil (output) register.
•
16: Write Registers
—Write to an Analog Output register.
•
Destination Register
—Enter the starting I/O register number in the destination
device that the Modbus mapping will transfer I/O to/from.
•
Device ID
—Enter the Modbus device ID of the destination device
•
Comms Fail Register
—Enter the onboard local I/O register number to store the
communication status for the specified mapping. The register will be set to one
of the following:
•
0 if communications is successful
•
0xFFFF if there is no connection to the specified server
•
0xFFxx where
“xx” is the Modbus Exception Code (see Appendix E for
information on the codes).
Add Entry Adds an entry to the Modbus Master Mappings table.
Delete Entry Deletes an selected entry from the Modbus Master Mappings table.
Save Changes Save changes to non-volatile memory.
Save and Activate
Changes
Save changes to non-volatile memory and activate the process.