Supported Modbus Functions; Description; Function Code 01H - GE Multilin MM3 Motor Manager 3 Instruction Manual

CHAPTER 8: COMMUNICATIONS
8.2.1

Description

8.2.2 Function Code
01h
NOTE
MM3 MOTOR MANAGER 3 – INSTRUCTION MANUAL
8.2

Supported Modbus Functions

The following functions are supported by the MM3 Motor Manager 3:
• Function code 01 - Read coil status
• Function code 03 - Read setpoints and actual values
• Function code 04 - Read setpoints and actual values
• Function code 05 - Execute operation
• Function code 06 - Store single setpoint
• Function code 07 - Read device status
• Function code 08 - Loopback test
• Function code 10 - Store multiple setpoints
Modbus implementation: Read coil status
MM3 Motor Manager 3 implementation: Read last command operation
This function code allows the master to read back which command operation was last
performed using modbus function code 05: force single coil/execute operation. Upon
request of coil/operation status, the MM3 Motor Manager 3 will set a bit corresponding to
the last operation performed. The operation commands are listed in format code F22 in
Modbus Data Formats on page 8–43.
Operation 0 will be set (1) if no operations have been performed since the MM3 Motor
Manager 3 has been powered up.
For example, a request slave 17 to respond with status of six operations, starting at
operation 10, after performing command operation 13 (manual inhibit) has the following
format:
Master transmission
Slave address
Function code
Operation starting address
Number of operations to read
CRC
Slave response
Slave address
Function code
Byte count
Data byte (see definition below)
CRC (low, high)
The data byte definition is as follows:
Data 1 = 08 (hex) =
Command operation
Bytes Example
1 11
1 01
2 00 0A
2 00 06
2 9E 9A
Bytes Example
1 11
1 01
1 01
1 08
2 54 83
0 0 0 0
N/A N/A 15 14
SUPPORTED MODBUS FUNCTIONS
Description
message for slave 17
read binary status
start at operation 10
read six operations
computed CRC error code
Description
message from slave 17
read last command operation
6 operations = 6 bits:
only one byte is required
bit set for command 13
computed CRC error code
1 0 0
13 12 11
0
10
8–5