Mitsubishi Electronics MR-J2S- CL Time-outoperation, Retry operation, Communication Functions, 15

15. COMMUNICATION FUNCTIONS

15.7 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)

Controller (Master station)

Servo

(Slave station)

Message

100ms

300ms

E

O

T

Message

100ms

300ms

E

O

T

Message

100ms

300ms

E

O

T

Message

300ms*Time-out

15.8 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.

Controller (Master station)

Message Message Message

*Communication error

Servo

(Slave station)

S

T

X

Station number

or

group

S

T

X

Station number

or

group

S

T

X

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.

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