ioPAC 8020 Rugged Remote I/O
Using Modbus/TCP
B-3
Address Code
High Byte
Byte
Example: Force coil 3 (address 00003) ON in IOPAC 8020 module
01 05 00 03 FF 00
Response message format for function code 05:
The normal response is an echo of the query, returned after the coil state has been forced.
Command Body
Station
Address
Function
Code
Coil Address
High Byte
Coil Address Low
Byte
Force Data High Byte Force Data Low Byte
Function Code 06
Presets integer value into a single register.
Request message format for function code 06:
Command Body
Station
Address
Function
Code
Register Address
High Byte
Register Address
Low Byte
Preset Data High Byte Preset Data Low Byte
Example: Preset register 40002 to 00 04 hex in IOPAC 8020 module
01 06 00 02 00 04
Response message format for function code 06:
The normal response is an echo of the query, returned after the coil state has been preset.
Command Body
Station
Address
Function
Code
Register Address
High Byte
Register Address
Low Byte
Preset Data High Byte Preset Data Low Byte
Function Code 08
The remote device can be initialized and restarted, and all of its communications event counters are cleared.
Most notably, data field 0x55AA makes the remote device restart with EEPROM factory default setings.
Request message format for function code 08:
Sub Function
Data Field (Request)
Data Field (Response) Description
0x0001
0xff00
Echo Request Data
reset
0x0001
0x55AA
Echo Request Data
Reset with Factory
defaults
Function Code 15 (0F hex)
Forces each coil in a sequence of coils to either ON or OFF.
Request message format for function code 15:
Command Body
Station
Address
Function
Code
Start
Address
High Byte
Start
Address
Low Byte
Requested
Number of
Coil High
Byte
Requested
Number of
Coil Low
Byte
Byte
Count
Force Data
High Byte
Force Data
Low Byte
Example: Request to force a series of 10 coils starting at address 00017 (11 hex) in ioPAC 8020 module.
01 0F 00 11 00 0A 02 CD 01
The query data contents are two bytes: CD 01 hex, equal to 1100 1101 0000 0001 binary. The binary bits are
mapped to the addresses in the following way.
Bit: 1 1 0 0 1 1 0 1 0 0 0 0 0 0 0 1