Valhalla Scientific 4300C, Operation Manual

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If the SRQ line is asserted, the controller should then perform a serial poll to determine which device
requires service. The 4300C will return an ASCII zero (0) in response to a serial poll if it did not generate
the SRQ. A non-zero number will be returned if it was responsible for asserting SRQ. A serial poll is
performed in HP Basic using the command:
SPOLL(712) which would poll the device at address 12.
Output Data Terminator
The "D" command determines the type and quantity of terminators that will be used to signal the end of
any data that the 4300C returns to the controller. This includes measured resistance data as well as the
response to the "configuration status" query. The 4300C interprets this command as follows:
D0 C
R
L
F
(default)
D1 C
R
L
F
with EOI asserted
D2 C
R
L
F
D3 C
R
L
F
with EOI asserted
The D1 selection is preferred by IEEE-488.2 systems such as National Instruments
®
.
Test Current Control
The " C " command is used to enable or disable the output of the current source. This command is decoded
as follows:
C0 Turns the test current off
C1 Turns the test current on
Display Hold
The display of the 4300C may be frozen from the GPIB bus using the commands listed below. While in the
"hold" mode the A-to-D converter is still performing measurements, but the results are not sent to the
4300C's display or to the IEEE output buffer. Therefore, once a trigger is sent or tracking is resumed, the
display will instantly reflect the latest measurement. The 4300C interprets these commands as follows:
T selects continuous tracking mode (default)
S selects hold mode; also used to trigger a single reading while holding
Temperature Compensation
The automatic temperature compensation mode (TCM) feature of the 4300C may be enabled or disabled
from the GPIB. If TCM mode is enabled the readings are automatically adjusted by the temperature sensor
attached to the front of the 4300C.
N selects normal mode; TCM off
A selects TCM on