User`s guide

RIGOL Chapter 2 Front Panel Operations
2-86 M300 User’s Guide
serial port receiving devices via this interface.
Press Utility  I/O  RS232 to enter the interface.
1 Print
Use the up/down direction keys to select Print and use the left/right direction
keys to select “ON” or “OFF” to enable or disable the measurement data output
function of the serial port. After connecting the instrument and the computer via
RS232 and enable the print function, the instrument will output the
measurement readings automatically through RS232 interface when the
instrument is measuring. At this point, you can capture the readings using serial
port data acquisition tool.
2 Parity
Use the up/down direction keys to select Parity and use the left/right direction
keys to set the parity to “None” (8 data bits), “Odd” (7 data bits) or “Even” (7
data bits). Please select a parity that matches the PC or DTE. When you set the
parity, you are also indirectly setting the number of data bits. The current setting
is stored in the non-volatile memory.
3 Flow Control
Use the up/down direction keys to select Flow and use the left/right direction
keys to select “NONE”, “XON/XOFF”, “DTR/DSR”, “RTS/CTS” or “MODEM”. Please
select a flow control mode that matches the PC or DTE.
 NONE
In this mode, 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”
character (13H) is received. When the “XON” character (11H) 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 “False” when the input
buffer is almost full (approximately 100 characters) and sets the pin “True”
when space is available again.