8 COMMUNICATION FUNCTION (MITSUBISHI ELECTRIC AC SERVO PROTOCOL) [A]
8.2 Communication specifications
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8
8.2
Communication specifications
Outline of communication specifications
The servo amplifier returns data upon receipt of a command. The device that gives the command (such as a personal
computer) is a master station, and the device (servo amplifier) that returns data in response to the command is a slave station.
When fetching data successively, give commands to the slave station from the master station repeatedly so that the slave
station sends data.
Setting servo parameters
When the RS-422 communication function is used to operate the servo, set the communication specifications of the servo
amplifier with servo parameters.
The settings of the servo parameters are enabled after the power is cycled.
Serial communication baud rate
Select a communication speed with [Pr. PC21.1 RS-422 communication - Baud rate selection]. Match this value to the
communication speed of the sending side (master station).
RS-422 communication response delay time
Set the time from when the servo amplifier (slave station) receives communication data until when it returns data. Setting [Pr.
PC21.2 RS-422 communication - Response delay time selection] to "1" (enabled) will return data in 800
μ
s or longer.
Setting station numbers
Set the station No. of the servo amplifier in [Pr. PC20 Station No. setting]. The setting range is 0 to 31.
Item
Description
Baud rate [bps]
9600/19200/38400/57600/115200 asynchronous system
Transfer code
Start bit
Data bit
Parity bit
Stop bit
1 bit
8 bits
1 bit (even number)
1 bit
Transfer method
Character method
Half-duplex communication method
Servo parameter
Description
PC21.1
RS-422 communication - Baud rate selection
0: 9600 [bps] (initial value)
1: 19200 [bps]
2: 38400 [bps]
3: 57600 [bps]
4: 115200 [bps]
Servo parameter
Description
PC21.2
RS-422 communication - Response delay time selection
0: Disabled (initial value)
1: Enabled
Setting "1" will return data with a delay of 800
μ
s or longer.
0
1
2
3
4
5
6
7
(LSB)
(MSB)
1 frame (11 bits)
Data
Start
Parity
Stop
Next
start