Mitsubishi Electric MR-J4, Instruction Manual

Page: 537 / 794

14. COMMUNICATION FUNCTION (MITSUBISHI GENERAL-PURPOSE AC SERVO PROTOCOL)
14 - 8
14.3.6 Retry processing
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 processing). A
communication error occurs if the above processing is repeated and results in the error three or more
consecutive times.
STX
Message Message
*Communication error
Message
Station No. Station No. Station No.
Controller side
(master station)
Servo side
(slave station)
STX STX
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 processing is performed three times.
14.3.7 Initialization
After the slave station is switched on, it cannot return to communication until the internal initialization
processing terminates. Hence, at power-on, ordinary communication should be started after.
(1) Wait for 3.5 s or longer after the slave station is switched on.
(2) Check that normal communication can be made by reading the parameter or other data which does not
pose any safety problems.