App - 32 App - 32
MELSEC-Q
APPENDIX
Appendix 7.2.3 DR (DSR) control enabled
The data transmission from the BASIC program is controlled depending on whether
the DR (DSR) control signal is ON or OFF at the RS-232C interface on the
communication side.
When the DR (DSR) control signal is ON, the data transmission starts or continues.
When the DR (DSR) control signal turns OFF, the data transmission stops. When the
data transmission stops due to the DR (DSR) control signal being turned off, the
remaining data will continue to be sent when the DR (DSR) control signal turns ON
again later.
(BASIC program)
ZOPEN • • • •
ZSEND • • • •
Communication module
Channel open
Send buffer
(OS)
Transmission result
External device
Waiting to send
DR control
signal
OFF
DR control
signal
ON
Data
Data
A
D51H
DR control
signal
ON
The CS (CTS) control has the same control function as the DR (DSR) control.
Determine which of the control functions of the communication module to use depending
on the external device's specifications.
