Leadshine Technology EM2RS Series - Modbus RTU; Communication Specifications; Modbus Function Codes (FC)

EM2RS Modbus RS485 Stepper Drive User Manual
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4 Modbus RTU
4.1 Communication Specifications
Items
Specifications
Remarks
Communication
Communication
Port
RS485 and RS232
RS232 only for fine tuning
RS485 for motion control
Baud Rate
9600/19200/38400/115200[bps]
Parameter setting
Synchronous
Mode
Start / Stop Synchronization
-
Communication
Mode
Half-duplex, Master-slave Mode
Slave/slave communication is prohibited
Character
Composition
Starting bit:1bit
Data length:8bit
Check bit:even/ odd/ no
Stop bit:0/1/2
Parameter setting
Protocol
Communicating
Protocol
Modbus RTU
ASCII is not supported
Slave ID
0:broadcast
1-31:valid sub-devices Numbers
Parameter setting
Function code
(FC)
Function code
(FC)
Function
-
0x03
Read single or
multiple data
0x06
Write value to
single data
0x10
Write value to
multiple data
Check Mode
CRC-16
Left is Low-bit, Right is high-bit
Message Length
Variable, the max length is 200byte
-
Single message communication rate of RS485: (Unit: ms)
Baud rate
Start receiving to send
completion time
Receive wait
time
Time from transmission
completion to recovery of
receiving state
Total
115200
2.44
0.64
0.6
3.08
38400
5.5
1.16
0.46
7.12
19200
10.76
2.2
0.38
13.34
9600
20.5
3.8
0.6
24.9
4.2 Modbus Function Codes (FC)
The current supported function codes as below:
Function
Code (FC)
Type
Description
03
Read Holding Registers
Requests content of holding registers