RS485/MODBUS Protocol E-3
MN762
E.6 Communication Specifications
Table E-4 Communication Specifications
Communication Speed
9600, 19200, 38400, 57600, 115200 bps selectable
Control Procedure
Asynchronous communication system
Communication
Half Duplex
Characters (Data bits)
ASCII (8 bit)
Start bits
1 bits
Stop bits
1 bits
Check Sum
2 byte CRC
Parity
None
E.7 Communications Protocol (MODBUS-RTU)
Use MODBUS-RTU protocol (Open Protocol). Requires computer or other host to be network Master and inverters to be
Slaves. Inverters respond to Read/Write commands from the Master.
Table E-5 Modbus-RTU Protocol
Register
Upper byte
Lower Byte
Command
Type
1*
Command
03,06
R/W
2*
Speed reference
03,06
R/W
3*
Reserved
03,06
R/W
4*
Modbus ramp control time
03,06
R/W
5
Reserved
03
R
6*
Error code
Drive status
03
R
7*
Motor speed
03
R
8*
Motor current
03
R
9*
Reserved
03
R
10
Reserved
03
R
11
Digital input status
03
R
12
Rating ID
03
R
13
Power rating
03
R
14
Voltage rating
03
R
15
IO processor software version
03
R
16
Motor control processor software version
03
R
17
Drive type
03
R
18
Reserved
03
R
19
Reserved
03
R
20
Analog 1 input result
03
R
21
Analog 2 input result
03
R
22
Speed reference value
03
R
23
DC bus voltages
03
R
24
Drive temperature
03
R
25 to 30
Reserved
03
R
*Registers are available in standard field bus gateway configuration.
