Mitsubishi Electric MELSERVO MR-J3-xT, Instruction Manual

Page: 426 / 471

15 - 8
15. COMMUNICATION FUNCTION
15.3.5 Time-out operation
The master station transmits EOT when the slave station does not start reply operation (STX is not received)
300ms after the master station has ended communication operation. 100ms after that, the master station
retransmits the message. Time-out occurs if the slave station does not answer after the master station has
performed the above operation three times. (Communication error)
E
O
T
300ms
100ms
E
O
T
300ms
100ms
E
O
T
300ms
100ms
300ms
*Time-out
Controller
(Master station)
Servo
(Slave station)
Me
ss
ag
e
Me
ss
ag
e
Me
ss
ag
e
Me
ss
ag
e
15.3.6 Retry operation
When a fault occurs in communication between the master and slave stations, the error code in the response
data from the slave station is a negative response code ([B] to [F], [b] to [f]). In this case, the master station
retransmits the message which was sent at the occurrence of the fault (Retry operation). A communication
error occurs if the above operation is repeated and results in the error three or more consecutive times.
M
essage
Me
ssage
Me
ss
ag
e
*Communication error
Controller
(Master station)
Servo
(Slave station) S
T
X S
T
X S
T
X
Station number
or
group
Station number
or
group
Station number
or
group
Similarly, when the master station detects a fault (e.g. checksum, parity) in the response data from the slave
station, the master station retransmits the message which was sent at the occurrence of the fault. A
communication error occurs if the retry operation is performed three times.