Mitsubishi Electric FR-A700 Technical Manual page 426

(1) Communication specifications
Item
Communication protocol
Conforming standard
Number of connectable devices
Communication speed
Control procedure
Communication method
Character system
Start bit
Stop bit length
Communication
specifications
Parity check
Error check
Terminator
Waiting time setting
(2) Overview
The Modbus protocol is the communication protocol developed by Modicon for Programmable controller.
The Modbus protocol performs serial communication between the master and slave using the dedicated message
frame. The dedicated message frame has the functions that can perform data read and write. Using the functions, you
can read and write the parameter values from the inverter, write the input command of the inverter, and check the
operating status. In this product, the inverter data are classified in the holding register area (register addresses 40001 to
49999). By accessing the assigned holding register address, the master can communicate with the inverter which is a
slave.
There are two different serial transmission modes: ASCII (American Standard Code for Information Interchange) mode
and RTU (Remote Terminal Unit) mode. This product supports only the RTU mode in which 1-byte (8-bit) data is
transmitted as-is.
Only the communication protocol is defined by the Modbus protocol, and the physical layer is not stipulated.
Description
Modbus-RTU protocol
EIA-485(RS-485)
1:N (maximum 32 units), setting is 0 to 247 stations
Can be selected from 300, 600, 1200, 2400, 4800, 9600, 19200 and
Asynchronous
Half-duplex
Binary (fixed to 8 bits)
Select from the following three types
No parity, stop bit length 2 bits
Odd parity, stop bit length 1 bits
Even parity, stop bit length 1 bit
CRC code check
Unavailable
Unavailable
460
38400bps
1bit
PARAMETER
Related
Parameters
[Pr. 549]
[Pr. 117, 331]
[Pr. 118, 332]
[Pr. 120, 334]