Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 866

Serial Communications Instructions
3-23-6 RECEIVE VIA SERIAL COMMUNICATIONS UNIT: RXDU(255)
Purpose
Note
Ladder Symbol
Variations
Applicable Program Areas
Operands
Reads the specified number of bytes of data from one of the CJ-series Serial
Communications Unit's serial ports.
A CJ Unit Adapter is required to use CJ-series Serial Communications Units.
This instruction can be used in the CP1H CPU Units only. It cannot be used in
the CP1L CPU Units. If RXDU(255) is used in a CP1L CPU Unit, Error Flag
(ER) will be turned ON.
RXDU(255)
D
C
N
Variations Executed Each Cycle for ON Condition
Executed Once for Upward Differentiation
Executed Once for Downward Differentiation Not supported.
Immediate Refreshing Specification
Block program areas Step program areas
OK OK
The contents of the control words, C and C+1, are as shown below.
15 12 11 8 7 4
C
RS and ER signal control
0: No RS and ER signal control
Always 00
1: RS signal control
2: ER signal control
3: RS and ER signal control
15 12 11 8 7 4
C+1
Serial port number
0: Specify directly. (See note.)
1: Port 1
2: Port 2
Port number specifier
(Internal logical port)
Specify 0 to 7 or F.
(F: Automatic allocation)
D: First destination word
C: First control word
N: Number of bytes
0000 to 0100 hex (0 to 256)
Subroutines
OK
3 0
Byte order
0: Most significant bytes first
1: Least significant bytes first
3 0
Destination unit address (See note.)
Serial Communications Unit's unit
address (unit number + 10 hex)
Section 3-23
RXDU(255)
@RXDU(255)
Not supported.
Interrupt tasks
OK
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