2 Instruction Descriptions
2-666
NJ-series Instructions Reference Manual (W502)
First, data is received in No-protocol Mode from the serial port specified with Port and stored in the
receive buffer in the Serial Communications Unit. This instruction transfers the number of bytes speci-
fied with receive data size Size from the receive buffer to receive data array DstDat[].
After the data is transferred, the number of array elements that was actually stored in DstDat[] is
assigned to the number of receive data array elements RcvSize. If the amount of data in the receive
buffer is smaller than Size, all of the data in the receive buffer is transferred to DstDat[]. The number of
array elements that was actually stored in DstDat[] is assigned to RcvSize. The receive buffer is cleared
after the data is transferred.
Device variables are used in the user program to recognize the start code and end code in the receive
data. The start and end codes are deleted from the receive data before it is stored in DstDat[].
If you add start and end codes, the maximum number of bytes to receive is 259 (1-byte start code, 2-
byte end code (for CR+LF specification), and 256 bytes of send data).
The data type of destination port Port is the structure _sPORT. The specifications are as follows:
Function
Code to attach Device variable for port 1 Value
Specified start code
P1_NopStartCodeYNCfg TRUE
P1_NopStartCodeCfg Start code (16#00 to
16#FF)
Specified end code
P1_NopEndCodeYNCfg TRUE
P1_NopCRLFCfg FALSE
P1_NopEndCodeCfg End code (16#00 to
16#FF)
CR+LF as end code
P1_NopEndCodeYNCfg TRUE
P1_NopCRLFCfg TRUE
Name Meaning Description Data type Valid range Unit Default
Port Destination
port
Destination port _sPORT --- --- ---
UnitNo Unit number Unit number of Serial
Communications Unit
_eUnitNo _CBU_No00 to
_CBU_No15
---
_CBU_
No00
PhysicPortNo Serial port
number
Serial port number on
Serial Communications
Unit
USINT 1 or 2 1
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