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3. LINKING TO THE A2CCPU
MELSEC-A
(1)
FROMnO instruction error detection X(n+4) and error-detection reset
Y (n+4)
Turns ON (latched) when instruction data which cannot be read
or written
from the
A2CCPU to the A64RDC is written. (The
RUN LED of the
A64RDC flashes.)
When the X(n+4) signal goes ON, its error code (see Table 7.1 in Section
7.1) is stored in the error code storage area (special registers D9180 to
D9193 of the A2CCPU) of the corresponding remote terminal number.
To restart communications, turn ON the error-detection reset Y(n+4) with
the sequence program
or, after resetting the
A2CCPU, write
"0" to
address 18 of the A64RDC to reset the A64RDC. Then,
the RUN LED
goes ON.
When the error-detection reset Y(n+4) goes ON, the
error code in the
error code storage
area (D9180 to D9193) and the corresponding
FROM/TO instruction information stored in the request-to-communicate
registration area are cleared.
FROM/TO instruction error
detection X(n+4)
OFF
Error-detection
reset
ON
Y(n+4)
OFF
ON
< >
To be turned ON and OFF
by the sequence program,
-
(2) Reset switch ON-detected flag X(n+5) and reset switch ON-detected flag
reset Y(n+5)
Turns ON (latched) when the reset switch of the A64RDC is set to reset.
When both
the reset switch ON-detected flag and the reset switch
ON-detected flag reset are
ON, the FROM/TO instruction information,
stored in the request-to-communicate registration area, with respect to
the corresponding remote terminal module, is cleared.
To restart communications, turn ON the reset switch ON-detected flag
reset Y(n+5) with the sequence program, or reset the A2CCPU.
the A64RDC
Reset switch on the front of
Reset switch ON-detected flag
ON
X(n+5)
OFF
ON
Reset switch ON-detected flag
reset
signal
Y(n+5)
OFF
To be turned ON and OFF
by the sequence program.
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