887
3. Instructions
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Serial Communications Instructions
3
DRXDU
DRXDU
Applicable Program Areas
Operands
C: Control word
z Operand Specifications
Instruction Mnemonic Variations
Function
code
Function
DIRECT RECEIVE VIA
SERIAL COMMUNICATIONS
UNIT
DRXDU @DRXDU 261
Reads the specified number of bytes of data from
the serial port of a CJ1W-SCU22/SCU32/SCU42
Serial Communications Unit to CPU Unit memory
starting at the specified first word. The data is
read in no-protocol mode with the start code and
end code (if any) specified in the allocated DM
Setup Area.
This instruction reads the data from the Serial
Communications Unit as soon as the instruction is
executed to achieve high-speed data reception.
Symbol
DRXDU
Area
Function block
definitions
Block program areas Step program areas Subroutines Interrupt tasks
SFC action or
transition programs
Usage OK OK OK OK OK OK
Operand Description Data type Size
D First destination word UINT Variable
C First control word UDINT 2
N Number of bytes 0000 to 0100 hex (0 to 256) UINT 1
Area
Word addresses
Indirect DM/EM
addresses
Con-
stants
Registers
TK CF
Pulse
bits
TR
bits
CIO WR HR AR T C DM EM
@DM
@EM
*DM
*EM
DR IR
Indirect
using IR
D
OK OK OK OK OK OK OK OK OK OK
---
---
--- OK --- --- --- ---C
OK
N OK
DRXDU(261)
D
C
N
D: First destination word
C: First control word
N: Number of bytes
0000 to 0100 hex (0 to 256)
15 8 011 37412
C
15 8 011 37412
C+1
Destination unit address (See note.)
Serial Communications Unit's unit
address (unit number + 10 hex)
Serial port number
1: Port 1
2: Port 2
Always 0
Always 00
Byte order
0: Most significant bytes first
1: Least significant bytes first
RS and ER signal control
0: No RS and ER signal control
1: RS signal control
2: ER signal control
3: RS and ER signal control
00
0
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