Mitsubishi Electric Melservo-J3 Series MR-J3-B, Instruction Manual

Page: 517 / 802

15 - 8
15. COMMUNICATION FUNCTION
15.3.6 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. A communication error occurs if the
above processing is repeated and results in the error three or more consecutive times.
M
essage
M
e
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 processing is performed three times.
15.3.7 Initialization
After the slave station is switched on, it cannot reply to communication until the internal initialization processing
terminates. Hence, at power-on, ordinary communication should be started after.
(1) 1s or more time has elapsed after the slave station is switched on; and
(2) Making sure that normal communication can be made by reading the parameter or other data which does
not pose any safety problems.