Instruction manual

13 - 8
13. COMMUNICATION FUNCTION
13.3.5 Time-out operation
The master station transmits EOT when the slave station does not start reply operation (STX is not received)
300[ms] after the master station has ended communication operation. 100[ms] 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
Message Message Message
Message
*Time-out
Controller
(Master station)
Servo
(Slave station)
13.3.6 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.
Message Message Message
*Communication error
Controller
(Master station)
Servo
(Slave station)
S
T
X
S
T
X
S
T
X
Station number Station number Station number
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.