ControlByWeb X-600M - Page 103

X-600M Users Manual Modbus Operation
lap. Discrete is a binary or boolean value, 1 or 0.
Function codes, memory types, and addresses can be converted to the PLC addressing equivalent
using the table below. To use the table, look up the row corresponding to the Modbus function code.
Then take the desired X-600M feature address and add to it the address offset in the PLC address mode
column:
Input Address + PLC Base Address = PLC Address
For example, to read discrete Input 2:
Input Address 1
PLC Base address 1001
PLC Address 1002
Programming the PLC to read from 1002 will return the value of Input 2.
Code Name Modbus
Function
X-600M Addresses
(Example)
Data Type PLC Address
Mode 485
PLC Address
Mode 584/984
Read Coils 01 0-3 (Relays 1-4) Discrete Addr + 1 Addr + 1
Read Discrete Inputs 02 0-3 (Inputs 1-4) Discrete Addr + 1001 Addr + 10001
Read Holding
Registers
03 16 (Vin) 32-bit float Addr + 4001 Addr + 40001
272-278 (Sensors 1-4) 32-bit float Addr + 4001 Addr + 40001
528-530 (Counters 1-2) 32-bit int Addr + 4001 Addr + 40001
Write Coils 05 0-3 (Relays 1-4) Discrete Addr + 1 Addr + 1
Write Multiple Coils 15 0-3 ( Relays 1-4) Discrete Addr + 1 Addr + 1
Write Multiple
Registers
16 528-530 (Counters 1-2) 32-bit int Addr + 4001 Addr + 40001
784-791 ( Relays 1-4) 32-bit float Addr + 4001 Addr + 40001
For 32-bit numbers, two registers must be read starting at the desired address (See section 5.3.3 for an
example).
Xytronix Research & Design, Inc. Page 101