Mitsubishi Electric MELSEC-A User Manual page 150

15. MULTIDROP LOCAL STATION
MELSEC-A
15.4 AJ71UC24 Control
Wait for Pre-
pptransmis- transmission Data transmission Data transmission Data transmission
Initialization slon sequence sequence sequence sequence sequence
AJ71 UC24
transmission
I----+
--
I
I I
scan
Power
2
!
XnO
T
(1) Pre-transmission sequence
When the power is switched on, the AJ71UC24 is initialized and waits
for the pre-transmission sequence from the master station.
(2) During the pre-transmission sequence, the local AJ71 UC24 confirms the
link status and I10 points.
(3)
Data transmission sequence
When the pre-transmission checks are complete, the data transmission
sequence is started automatically.
After the first transmission sequence is finished, XnO is switched on
(Assuming that the I10 unit number is 0).
(
The transfer of data between the PC CPU and AJ71 UC24 buffer must be
started in the sequence program after XnO switches on.
(4) When the master AJ71UC24 is connected to several slaves, XnO is
switched on after completion of the first data transmission sequence.