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3. Instructions
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Serial Communications Instructions
3
DRXDU
Example Programming
Using DRXDU(261) in Cyclic Tasks
When CIO 0.00 is ON and CIO 1559.06 (the Reception Completed Flag for port 1) is ON in the
following example, DRXDU(255) reads the data received from the general-purpose device connected to
serial port 1 of the Serial Communications Unit with unit number 2. The 10 bytes of received data are
written to the DM Area beginning at the rightmost byte of D100.
DRXDU
D100
D200
&10
1559.06
D
C
N
0.00
C: D200
0
0 7 815
0
11 12
0
0
Serial Communications Unit's unit address
(CPU Bus Unit's unit address)
12: Unit address + 10 hex
7 815
1
11 12
0
1
4 3
Always 0
0: No RS and ER signal control
1 2
4 3
1: Serial port No. 1
Serial Communications Unit's serial port specifier
D: D100
0 7 815
4 1 2
Most significant bytes Least significant bytes
D101
8 5 6
D102
A
B
1 2 3 4 5 6 7 8 A B C D E F G H I J K L
10 bytes
3412ST 56 78 AB CD
ST: Start code (e.g., 02 hex)
ED: End code (e.g., 03 hex)
Data received
D
3
7
C
H E F
L I J
G
K
D103
D104
EF GH IJ KL ED
C+1: D201
Note: Allocated DM Area Settings
• Start code/end code
D30204:
0
End code (e.g., 03 hex)
7 815
2
11 12
0 3
4 3
Start code (e.g., 02 hex)
0
• Start code/end code specifier
D30205:
0 7 815
1
11 12 4 3
1
End code specifier
1: Use end code
00: Unlimited (256 bytes max.)
1: Least significant byte to most significant byte
RS and ER signal control
Number of receive data bytes
Start code specifier
1: Use start code
Reception
Completed
Flag
Received in
specified
order:
Start and end codes added
according to setting in PC Setup
Always 0
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