Mitsubishi Electric MELSEC iQ-R Series User Manual page 57

Data reception by receive end code (for variable length reception)
This method is used to transmit data by adding the receive end code set in C24 at the end of a message transmitted from a
target device.
The receive end code can be changed according to the specifications of the target device. Arbitrary 1-character (1-byte) code
within the range of 00H to FFH can be designated.
Setting Description
0D0AH (default) The receive end code is not changed.
H Arbitrary code is designated for the receive end
code. (00H to FFH)
FFFFH No receive end code
• When C24 receives the receive end code data preset with Engineering tool by the user, it issues a reception data read
request to the program.
The read request from C24 allows the program to read the received data up to the receive end code received from the
target device.
• C24 issues a reception data read request to the CPU module in the cases below, according to the setting value of the
receive end code.
■When receive end code is not changed (Default value: 0D0AH)
(CR+LF is added to the end of the message and sent from the target device.)
• When LF is received within the time set in the no-reception monitoring time (timer 0) after CR is received, C24 stores the
receive data up to CR+LF to the receive data storage area in the buffer memory and turns ON the 'CH reception data
read request' (X3/XA) to the CPU module.
Target device
C24
Reception data read request (X3/XA)
• If LF is not received within the time set in the no-reception monitoring time (timer 0) after CR is received, C24 stores the
received data up to CR to the receive data storage area on the buffer memory, and turns ON the following signals to the
CPU module.
Nonprocedural and no-reception monitoring time
Method 0 :'CH reception abnormal detection' (X4/XB)
Method 1 :'CH reception data read request' (X3/XA)
Target device
C24
Reception abnormal detection (X4/XB)
[Format is 0]
Reception data read request (X3/XA)
[Format is 1]
*1 It is used to receive a message of which the receive end code and receive end data quantity have not been determined by a timeout of
the non-reception monitoring time (timer 0) in the nonprocedural protocol. (Page 229 Nonprocedural no-reception monitoring time
method designation (Method 0/1))
*2 CR is handled as 1-byte data in the message.
Remarks
CR, LF is added to the end of the message and sent from the target device.
The designated receive end code data is added to the end of the message and
sent from the target device.
Data reception by receive end data quantity is available.
Timer 0
L
C
setting time
R F
*1
Timer 0
C
setting time
R
(*2)
3 DATA COMMUNICATION USING NONPROCEDURAL PROTOCOL
3.1 Receiving Data from Target Device
3
55