Receive Via Serial Communications Unit: Rxdu(255) - Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual

Serial Communications Instructions

3-24-6 RECEIVE VIA SERIAL COMMUNICATIONS UNIT: RXDU(255)

Purpose
Ladder Symbol
Variations
Applicable Program Areas
Operands
Reads the specified number of bytes of data from one of the Serial Communi-
cations Unit's serial ports. (The Serial Communications Unit must be Ver. 1.2
or later).
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
OK
The contents of the control words, C and C+1, are as shown below.
15 12
C
15
C+1
Note The serial port's unit address can be specified directly by setting the serial
port number to 0 and setting the destination unit address to the serial port's
unit address. (Set the destination unit address to 80 hex + 4
port 1 or 81 hex + 4
RXDU(255)
D
C
N
Step program
areas
OK OK
11 8 7 4 3 0
Byte order
0: Most significant bytes first
1: Least significant bytes first
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
12 11 8 7 4 3 0
Destination unit address (See note.)
Serial Communications Unit's unit
address (unit number + 10 hex)
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)
unit number for port 2.)
Section 3-24
D: First destination word
C: First control word
N: Number of bytes
0000 to 0100 hex (0 to 256)
RXDU(255)
@RXDU(255)
Not supported.
Subroutines Interrupt tasks
OK
unit number for
1013