Buffer Memory And Data Location - Mitsubishi MELSEC-A AJ71PT3 User Manual

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3. SPECIFICATIONS
POINT
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(1) The buffer memory is cleared (to 0) and 2 written to
address 1 (number of retries) when the PC CPU is
powered up or reset.
(2) Any data must not be written to other than addresses
0, 1, 10 to 41, 90 to 93, 250 to 282, 300 to 555, 598 and
599 from the PC CPU.
(3) The reserved areas are used by the master module
system.
(4) Data in the read-only areas including the reserved
areas can be read from the PC CPU sequentially, e.g.
data can be read from the accumu lative fau Ity station
detection (addresses 90 to 93) and faulty station
detection (addresses 100 to 103) areas by using one
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FROM
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instruction.
3.4.2 Buffer memory and data location
(1) Number of remote I/O stations (address 0)
(a) Define the remote
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station range for 1/0 refresh.
(b) 1/0 refresh is performed for up to the remote 1/0 station
specified in address O.
For example, remote 1/0 stations 1 to 20 are refreshed when 20
is set to address O.
(c) Specify the last remote 1/0 station number connected to the
master module.
The value specified should include the number of occupied
stations if the last remote 1/0 station occupies two or more
stations, e.g. set 13 to address 0 to allow data link for up to
station 10 that occupies 4 stations.
(d) Defaults to O.
(e) Any value between 1 and 64 may be specified. Any value set
outside this range flags an initial data error when Y18 is
switched on.
(f) The number of remote 1/0 stations should be written to
address 0 with Y18 off as the value on the leading edge of Y18
is valid.
(2) Number of retries (address 1)
(a) Define the number of retries made to the faulty remote 1/0
station.
(b) Defaults to 2.
(c) Any value between 0 and 32 may be specified.
(d) The number of retries should be written to address 1 when
Y18 is off as the value on the leading edge of Y18 is valid.
(e) A communication error occurs if the faulty remote 1/0 station
cannot be restored after retry is made the specified number of
times.
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IB (NAl66164-A