Communication Specifications; Outline Of Communication; Parameter Setting - Mitsubishi Electric MELSERVO-J3 Series Handbook

Part 6: Common Reference Material

4.2 Communication specifications

4.2.1 Outline of communication

Receiving a command, this servo amplifier returns data. The device which gives the command (e.g. personal
computer) is called a master station and the device (servo amplifier) which returns data in response to the
command is called a slave station. When fetching data successively, the master station repeatedly
commands the slave station to send data.

4.2.2 Parameter setting

When the RS-422 communication function is used to operate the servo, set the communication
specifications of the servo amplifier with the parameters.
To enable the parameter values, cycle the power after setting.
(1) Serial communication baud rate
Select the communication speed. Match this value to the communication speed of the sending end
(master station).
(2) RS-422 communication response delay time
Set the time from when the servo amplifier (slave station) receives communication data to when it
returns data. Set "0" to return data in less than 800 μs or "1" to return data in 800 μs or longer.
(3) Station No. setting
Set the station No. of the servo amplifier to [Pr. PC20]. The setting range is station No. 0 to 31.
Item
Baud rate [bps]
Transfer code
Transfer method
(LSB)
Start 0 1 2
[Pr. PC21]
[Pr. PC21]
Definition
9600/19200/38400/57600/115200 asynchronous
system
Start bit
Data bit
Parity bit
Stop bit
Character method
3 4 5 6
Data
1 frame (11 bits)
Serial communication baud rate
0: 9600 [bps] 3: 57600 [bps]
1: 19200 [bps] 4: 115200 [bps]
2: 38400 [bps]
RS-422 communication response delay time
0: Disabled
1: Enabled (responding after 800
6 - 76
1 bit
8 bits
1 bit (even)
1 bit
Half-duplex
communication method
(MSB)
Next
start
7 Parity Stop
s or longer delay time)