HP 34970A manual Gh6

Chapter 5 Remote Interface Reference

RS-232 Interface Configuration

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You can select one of several “ xmethods to coordinate the transfer of data between the instrument and your computer or modem.

∙b : 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.

∙mcb6mcSS: 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.

∙Qhf6Qgf: In this mode, the instrument monitors the state of the DSR (data set ready) line on the RS-232 connector. When the line goes true, the instrument sends data over the interface. When the line goes false, the instrument stops sending information (typically within six characters). The instrument sets the DTR line false when the input buffer is almost full (approximately 100 characters) and releases the line when space is available again.

∙ fhg6Phg: This mode operates the same as the Qhf6Qgf mode but 5

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 instrument sends data over the interface. When the line goes false, the instrument stops sending information (typically within six characters).

The instrument sets the RTS line false when the input buffer is almost full (approximately 100 characters) and releases the line when space is available again.

∙ayz : This mode uses the DTR/DSR and RTS/CTS lines to control the flow of data between the instrument and a modem. When the RS-232 interface is selected, the instrument sets the DTR line true. The DSR line is set true when the modem is on-line. The instrument 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 instrument sets the RTS line false when the input buffer is almost full (approximately 100 characters) and releases the line when space is available again.

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