● The communication specifications are given below.
Waiting time setting
Tab. 5-240: Communication specifications
● The MODBUS® communication protocol was developed by Modicon for programmable control-
● The MODBUS® protocol uses exclusive message frames to perform serial communication between
a master and slaves. These exclusive message frames are provided with a feature called "functions"
that allows data to be read or written. These functions can be used to read or write parameters
from the inverter, write input commands to the inverter or check the inverter's operating status,
for example. This product classifies the data of each inverter into holding register area (register
address 40001 to 49999). The master can communicate with inverters (for instance,. slaves) by
accessing pre-assigned holding register addresses.
There are two serial transmission modes, the ASCII (American Standard Code for Information Inter-
change) mode and the RTU (Remote Terminal Unit) mode. However, this product supports only
the RTU mode, which transfers 1 byte data (8 bits) as it is. Also, only communication protocol is
defined by the MODBUS® protocol. Physical layers are not stipulated.
MODBUS® RTU protocol
1:N (maximum 32 units), setting is 0 to 247 stations
Selected among 300/600/1200/2400/4800/9600/19200/38400/57600/
Binary (fixed at 8 bits)
Select from the following three types:
Stop bit length
No parity check, stop bit length 2 bits
Odd parity check, stop bit length 1 bit
Even parity check, stop bit length 1 bit
CRC code check
(N) Operation via communication and its settings
5 - 489