Mitsubishi Electric MELSEC-A User Manual page 49

3. SPECIFICATIONS
MELSEC-A
Described below are the operations or processing at the timings from ( I ) to
(7) shown i n the figures on the previous page.
(The mode switching pattern concerned is affixed to each number.)
(1) (NormalIForced)
Before switching the mode, communicate the data to provide an interlock
between the external device and the AJ71 UC24 (sequence program).
This is because the mode switching conditions must be set for all con-
nected devices.
1
(2) (NormalIForced) Write the next mode number from the sequence program to the AJ71 UC24
buffer memory's mode switching designation area (address 119H).
next mode number to be switched
The same number as the mode setting switch number shown in Section
4.3.1 is specified.
I I
(Example)
1
(3) (Normal)
(4) (Normal)
(Forced)
(5) (Normal)
(Forced)
I
Oesignated
I
RS-232C
1
RS-4221485
(
Value
(Set for normal mode switching)
I : Request to switch the mode
(Set for forced mode switching)
0:
Normal mode switching
8: Forced mode switching
The request-to-switch-mode signal (Y(n+1)9) is turned OFF from the PC
CPU.
The AJ71UC24 turns OFF its READY signal (Xn7), executing the following
operations:
AJ71 UC24 mode switching
Returning the data in the AJ71 UC24 buffer memory's special applications
area to the default state
(except for the mode switching designation area (address 119H))
As soon as writing data to buffer memory address 119H has been completed,
the AJ7iUC24 turns OFF its READY signal (Xn7), executing the following
operations:
AJ71 UC24 mode switching
Returning the data in the AJ71UC24 buffer memory's special applications
area to the default state
(except for the mode switching designation area (address 119H))
After completing step (4), the AJ71UC24 turns ON both its READY signal
(Xn7) and the switch-completed signal (Xn9).
After completing step (4), the AJ71UC24 turns ON its READY signal, over-
writing 02H to the higher bytes in the buffer memory's mode switching
designation area.
'
I
u t c h e d to this mode number (designated in stel,
(2))
Mode switching completed.
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