App - 37 App - 37
MELSEC-Q
APPENDIX
Appendix 7.3.2 Flow of received data when a break character is specified
The examples in the following figures illustrate the flow of received data when 0 is
specified in the receive buffer specification (no receive buffer) and when 1 to 1024 is
specified (receive buffer available) when the communication channel is opened. The
0D
H
(
C
R
) data is specified as the single break character and a maximum of 10 bytes is
requested to be received.
(1) When there is no receive buffer
"A"
"B"
"C"
"D"
"E"
"F"
(BASIC program)
Communication channel open
Result of channel opening
Receive request
Communication module
Data
(OS)
Ig
n
o
re
d
Input elements
"A"
"B"
"C"
"D"
"E"
"F"
Reception
result
ZOPEN to
ZRECEIVE to
"C
R"
Data prior
to reception
The received data after the receive
request is made is returned.
Ignor
ed
Data
"C
R"
(2) When a receive buffer is available
(BASIC program)
Communication channel open
Result of channel opening
Receive request
Receive buffer
Communication module
Data
"1"
"2"
"3"
"4"
"5"
"6"
"7"
"8"
(OS)
"1"
"2"
"@"
Ig
no
re
d
"9"
"0"
"@"
"@"
"@"
"@"
Input elements
Reception
result
"3"
"9"
"0"
"@"
"@"
"@"
"@"
"A"
"B"
ZOPEN to
ZRECEIVE to
"@"
"@"
"A"
"B"
"C"
"@"
Reception
result
"1"
"2"
"3"
"4"
"5"
"6"
"7"
"8"
"9"
"0"
Receive
request
ZRECEIVE to
Data prior
to reception
"@"
"@"
"@"
"@"
"@"
"@"
"C
R"
"C
R"
"C
R"
