Mitsubishi MELSEC Q Series User Manual page 23

1 OVERVIEW
PLC CPU
Automatic refresh
X
Automatic refresh
Y
Automatic refresh
W
Automatic refresh
W
PLC CPU
RIWT
RIRD
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(4) Intelligent device station communication
Communication between the master station and the intelligent device station
uses two types of transmission methods: cyclic transmission and transient
transmission (see Section 4.2.4).
(a) Cyclic transmission
Signals for handshaking with the intelligent device station (positioning start,
positioning complete, etc.) are communicated using the remote input RX and
remote output RY. Numeric data (positioning start number, present feed
value, etc.) is communicated using remote registers RWw and RWr.
Master station
Remote
input
RX
Remote
output
RY
Remote
register
RWw
Remote
register
RWr
(b) Transient transmission
Read (RIRD) or written (RIWT) operation of the intelligent device station
buffer memory can be performed at any timing.
Intelligent device station
Remote
Link scan
Remote
Link scan
output
Remote
Link scan
register
RWw
Remote
Link scan
register
Master station
Transient transmission
Transient
transmission
area
Transient transmission
input
RX
RY
RWr
Intelligent device station
Buffer memory
MELSEC-Q
Servo amplifier
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