Writing The Initial Data - Mitsubishi MELSEC-A AJ71PT3 User Manual

5. PROGRAMMING
_ _ _ _ _ _ _ _ _ _----.lIMELSEC;4
5.2
Writing the Initial Data
Note the following when writing the initial data to the master
module buffer memory.
The initial data includes the number of remote I/O stations
(address 0), number of retries (address 1), and partial refresh
station (addresses 250 to 282).
The partial refresh stations must be defined only when partial
refresh type remote I/O stations are used. For information on
setting, see Section 5.4.2.
(1) Buffer memory assignment related to initial data
•
Address (Decimal)
o
Number of remote 110 stations
1 Number of retries
(2) Number of remote I/O stations (address 0)
(a) Define the remote I/O station range for I/O refresh.
(b) I/O refresh is performed for up to the remote I/O station
specified in address O.
For example, remote I/O stations 1 to 20 are refreshed
when 20 is set to address O.
(c) Specify the last remote I/O station number connected to
the master module.
The value specified should include the number of occupied
stations if the last remote I/O 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.
•
(3) Number of retries (address 1)
(a) Define the number of retries made to the faulty remote I/O
station.
(b) Defaults to 2.
(c) Any value between 0 and 32 may be specified.
(d) A communication error occurs if the faulty remote I/O
station cannot be restored after retry is made the specified
number of times.
(4) Initial data write timing
The initial data should be written when Y18 is off because the
I
values on the leading edge of Y18 are valid.
(5) Program example
The following program sets the number of remote I/O stations
to 20 and the number of retries to 3.
ae
l
Pulses the initial data write command.
De Sets 20 (number of remote 110 stations area) to DO.
01
Sets 3 (number of retries) to D1.
K
Writes the initial data to master module buffer
2
memory.
ee
CNOlJ
- - - - - - - - - - - - - < C N O U
I
- - - - - - - { n o
~'iHl0
Initial data
F ".
~
rite command
, I f - - - - - - - - - - - - - { C P L S
'~l ~
5-2
IB (NAJ 66164·A