
2.LCD-MOUNTED TYPE 16i/18i/21i-A, Power Mate i-D/H OPERATION B-62714EN/04
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Restrictions on the global I/O transfer function
Conditions for taking in DO data from a remote slave station to the master
station
When the two conditions below are satisfied, DO data from a remote
slave station to the master station is taken in.
Condition 1 : 48 bytes ≥ x bytes ≥ y bytes
where
x : Size of DI data from the master station to the local slave
station
y : Size of DO data from a remote slave station to the master
station
Condition 2 : Station m ≥ Station n
where
m : [MAX SLAVE NO] set at the local slave station
n : Station number of a remote slave station
Example:
When the station number of the local slave station is 2, there are
five remote slave stations, and each slave station is set as
follows:
- Setting of slave station #1: DO data size = 16 bytes
- Setting of slave station #2: [MAX SLAVE NO] = 4,
[STATION NO] = 2, [DI/DO MAP MODE] =2, [DI/DO
DATA SIZE] = 32
- Setting of slave station #3: DO data size = 32 bytes
- Setting of slave station #4: DO data size = 48 bytes
- Setting of slave station #5: DO data size = 8 bytes
According to the restrictions on global I/O transfer:
- Slave station #4 does not satisfy condition 1.
- Slave station #5 does not satisfy condition 2.
So, slave station #2 takes in only DO data from slave station #1
to the master station and DO data from slave station #3 to the
master station.
DI data allocation for slave station #2
DO data from slave station #1
(16 bytes) 32 bytes
Not used
(16 bytes)
Not used
(Area for the local station number)
32 bytes
DO data from slave station #3 32 bytes
Not used
(For slave station #4)
32 bytes