Rs-232 Handshake Methods - Agilent Technologies 33250A User Manual

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Chapter 4 Remote Interface Reference
RS-232 Interface Configuration

RS-232 Handshake Methods

You can select one of several handshake (or "flow control") methods to
coordinate the transfer of data between the function generator and your
computer or modem. The default handshake is DTR/DSR.
• None: In this mode, data is sent and received over the interface
without any flow control used. When using this method, use a slower
baud rate (< 9600 baud) and avoid sending more than 128 characters
without stopping or reading a response.
• DTR/DSR: In this mode, the function generator monitors the state of
the DSR (data set ready) line on the RS-232 connector. When the line
goes true, the function generator sends data over the interface.
When the line goes false, the function generator stops sending
information (typically within six characters). The function generator
sets the DTR line false when the input buffer is almost full (about 100
characters) and releases the line when space is available again.
• Modem: This mode uses the DTR/DSR and RTS/CTS lines to control
the flow of data between the function generator and a modem.
When the RS-232 interface is selected, the function generator sets the
DTR line true. The DSR line is set true when the modem is on-line.
The function generator sets the RTS line true when it is ready to
receive data. The modem sets the CTS line true when it is ready to
accept data. The function generator sets the RTS line false when the
input buffer is almost full (about 100 characters) and releases the line
when space is available again.
• RTS/CTS: This mode operates the same as the DTR/DSR mode but
uses the RTS (request to send) and CTS (clear to send) lines on the
RS-232 connector instead. When the CTS line goes true, the function
generator sends data over the interface. When the line goes false,
the function generator stops sending information (typically within six
characters). The function generator sets the RTS line false when the
input buffer is almost full (about 100 characters) and releases the line
when space is available again.
• XON/XOFF: This mode uses special characters embedded in the
data stream to control the flow. If the function generator is addressed
to send data, it continues sending data until the "XOFF" character
(13H) is received. When the "XON" character (11H) is received, the
function generator resumes sending data.
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