Modbus: Interoperability; Physical And Data Link Layer; Application Layer - Toshiba GRE110 Instruction Manual

Modbus: Interoperability

1. Physical and Data Link Layer

- RS485(EIA/TIA-485) 2-wire interface
- RTU mode only
- Coding System:
8–bit binary (1 start bit, 8 data bits, 1 parity bit, 1 stop bit)
Even parity
- Address setting range: 1-247
- Baud rate setting range: 9600 or 19200

2. Application Layer

(1) Modbus response format
FC Description
01 Read Coils
02 Read Discrete Inputs
03 Read Holding Registers
04 Read Input Register
05 Write Single Coil
06 Write Single Register
07 Read Exception status
08 Diagnostic
16 Write Multiple Registers
17 Report Slave ID
43 Read device Identification (SC:14)
For FC (Function Code) = 01, 02, 03, 04, 05, 06 and 16, the response format is the same as described
in "Modbus Application Protocol Specification V1.1b".
For other FCs, the response format is as following:
07 Read Exception status
Response Data
Output Data (1byte)
bit Description
0 IN SERVICE (LED)
1 TRIP (LED)
2 ALARM (LED)
3 RELAY FAIL (LED)
4 CB CLOSED (LED)
5 CB OPEN (LED)
6 Relay fail output (BO)
7 <Reserved>
Supplementary explanation
Returns remote control enable flag
Returns BIs or LED lamp status, etc.
-
Returns value of analog inputs
Remote command and Time synchronization
Need to specify record number
Returns relay and CB status
-
Current time setting, etc.
Returns device ID
Returns device information
 261 
6 F 2 T 0 1 7 2