Specifications

RIGOL Chapter 2 Command System
2-210 M300 Programming Guide
SYSTem:COMMunicate:RS232:FLOWcontrol
Syntax SYSTem:COMMunicate:RS232:FLOWcontrol
{NONE|XON/XOFF|DTR/DSR|RTS/CTS|MODem}
SYSTem:COMMunicate:RS232:FLOWcontrol?
Description Set or query the flow control mode of the RS232 interface.
Parameters
Name
Type
Range
Default
{NONE|XON/XOFF|DTR/DSR
|RTS/CTS|MODem}
Bool
NONE|XON/XOFF|DTR/DSR
|RTS/CTS|MODem
None
Explanation  Please select the flow control mode that matches the computer or DTE.
NONE
In this mode, the data is sent and received over the RS232 interface without any flow
control used. When this mode is selected, please select relatively slower baud rate
(lower than 9600 Baud) and please do not send data that is too long (longer than 128
characters) and does not contain end bit.
XON/XOFF
This mode is software flow control mode. This mode uses special characters embedded
in the data stream to control the flow. If the instrument is addressed to send data, it
continues sending data until the “XOFF” (13H) string is received. When the “XON”
(11H) string is received, the instrument resumes sending data.
DTR/DSR
This mode is hardware flow control mode. The instrument monitors the state of the
DSR pin. When the state goes “True”, the instrument sends data over the interface.
When the state goes “False”, the instrument stops sending data. The instrument sets
the DTR pin to “False” when the input buffer is almost full (approximately 100
characters) and sets the pin to “True” when space is available again.
RTS/CTS
This mode is hardware flow control mode and it operates in the same way as the
DTR/DSR mode. The instrument monitors the state of the CTS pin. When the state
goes “True”, the instrument sends data over the interface. When the state goes
“False”, the instrument stops sending data. The instrument sets the RTS pin to “False”
when the input buffer is almost full (approximately 100 characters) and sets the pin to
“True” when space is available again.
 The flow control mode of the RS232 interface is stored in the non-volatile memory
(refer to
Appendix C: Non-volatile Memory) and does not change when the power has
been off, after a Factory Reset (send the
*RST command) or after an Instrument
Preset (send the SYSTem:PRESet command).
Return
Format
The query returns NONE,XON/XOFF,DTR/DSR,RTS/CTS or MODEM.
Example
SYST:COMM:RS232:FLOW XON/XOFF
SYST:COMM:RS232:FLOW?
The query returns XON/XOFF.
Related
commands
SYSTem:COMMunicate:RS232:BAUD
SYSTem:COMMunicate:RS232:PARIty
SYSTem:COMMunicate:RS232:PRINt:STATe