Stanford Research Systems DS335, User Manual

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2-18 Sweeps & FSK
DS335 Synthesized Function Generator
RS232 Setup To set the DS335's RS232 interface press [SHIFT][2]. The RS232 enable
selection will be displayed. Use the UP/DOWN ARROW keys to enable the
RS232 interface. Press [SHIFT][2] again to display the RS232 baud rate
selection. The available baud rates of 300, 600, 1200, 2400, 4800, or 9600
baud can be set with the UP/DOWN ARROW keys.
NOTE: If no interface option is present the message "no RS232" will be
displayed when the RS232 menu is accessed. Only one of the GPIB and
RS232 interfaces may be active at a given time, the GPIB interface is
automatically disabled when RS232 is enabled.
User Service Requests While the GPIB is enabled the user may issue a service request (SRQ) by
pressing [SHIFT][4]. The message "srq sent" will be displayed, and the GPIB
LED will light. The GPIB LED will go off after the host computer does a serial
poll of the DS335. Note: the user service request is in addition to the usual
service requests based on status conditions (see PROGRAMMING section
for details).
Communications Data Press [SHIFT][2] three times to display the last 256 characters of data that
have been received by the DS335. This display is a 3 character window into
the DS335's input data queue that could be scrolled to view the previous 256
characters. The data is displayed in ASCII hex format, with each input
character represented by 2 hexadecimal digits. The most recently received
character has a decimal point indicator. Pressing [DOWN ARROW] scrolls
the display to the beginning of the queue, and [UP ARROW] scrolls to later in
the queue.
AUTO-TEST
Introduction The DS335 has a built-in test routine that allows the user to test a large
portion of instrument functionality quickly and easily. Self-test starts every
time the DS335 is turned ON.
SELF-TEST The DS335's self-test is always executed on power-up. The test checks
most of the digital circuitry in the DS335, and should end with the display
"test pass". If the self-test encounters a problem it will immediately stop and
display a warning message. See the TROUBLESHOOTING section for a list
and explanation of the error messages. If the DS335 fails its test it still may
be operated.
The DS335 tests its CPU and data memory, ROM program memory,
calibration constant integrity, the computer interfaces, and the modulation
program memory
Items not tested are the connections from the PC boards to the BNC
connectors, the 12-bit waveform DAC, the output amplifier, the offset and
amplitude control circuits, and the output attenuators.
CALIBRATION BYTES It is possible to recall and modify the DS335 factory calibration bytes. Please
refer to the Test and Calibration Chapter for more detail.