EM2RS Modbus RS485 Stepper Drive User Manual
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06
Preset Single Register
Writes to single holding register
10
Preset Multiple Registers
Writes to multiple holding register
4.2.1 Read Holding Registers FC= 03
Read Holding Registers Query (Master to Slave)
Read Holding Registers Response (Slave to Master)
Slave ID
00 - 1F
Slaver ID
00 - 1F
FC
03
FC
03
Address of beginning
register to be read
High
Number of data bytes in
message
High
Low
Low
Total number of registers
to be read
High
Data from registers (2 bytes
per register)
High
Low
Low
CRC
Low
CRC
Low
High
High
Example A: Read the value of a single register--peak current
Send message: 01 03 01 91 00 01 D3 1B
Receive message: 01 03 02 00 0A 38 43
Details as following:
Master->slave data:
Message:
01
03
01 91
00 01
D3 1B
Description:
Slave ID
FC
Register address
Number
of
registers read
CRC
Slave->master data:
Message:
01
03
02
00 0A
38 43
Description:
Slave ID
FC
Number of bytes
returned
Value of 0x01 91 CRC
Note: 0x0191-- output peak current, 000A(Hexadecimal)=10(decimal, unit: 0.1A), it means the current 1A.
Example B: Read multiple register values
Send message: 01 03 01 BC 00 06 05 D0
Receive message: 01 03 0C 00 00 00 02 00 00 00 01 00 00 00 04 B6 13
Details as following:
Master->slave data:
Message
01
03
01 BC
00 06
05 D0
Description
Slave ID
FC
Register address
Number
of
registers read
CRC
Slave>master data:
Message
01
03
0C
00 00
00 02
00 00
00 01
00 00
00 04
9D
B3
