Keithley 6512, Инструкция по эксплуатации

Страница: 60 / 156

IEEE-488 Programming
3-5
3.2.1 Calibration value (A)
Purpose
To send calibration values to the instrument when digitally calibrating the unit.
Format Ann.nnn
An.nnnE+n
Description One advanced feature of the Model 6512 is its digital calibration capabilities. Instead of the
more difficult method of adjusting a number of potentiometers, the user need only apply an ap-
propriate calibration signal and send the calibration value over the bus.
If the calibration value is outside the allowed range (±6% of nominal value), a number error will
occur, as indicated by the following message:
n Err
Once all functions and ranges have been calibrated, permanent storage of calibration parameters
must be performed, as described in paragraph 3.2.7.
Programming
The proper calibration signal must be connected to the instrument before attempting calibration.
Note See Section 7 for complete details on calibrating the instrument, either from the front panel or
over the bus.
Examples A1.9X Value = 1.9.
A1.9E-3X Value = 0.0019
3.2.2 Reading mode (B)
Purpose
To control the source of the data sent over the IEEE-488 bus.
Format B0 Electrometer reading
B1 Data store reading
B2 Maximum reading
B3 Minimum reading
Default Upon power-up, or after a DCL or SDC command, the instrument will be in the B0 (electrom-
eter) mode.
Description The reading mode command parameters allow the selection of the source of data that is trans-
mitted over the IEEE-488 bus. Through this command, you have a choice of data from the elec-
trometer, data store reading, or minimum and maximum values. Note that the commands
associated with data store are always available; however the suffix of the reading string will
show 000 if data store is disabled, as in NDCV+1.2345E+00,000. Minimum/maximum values
returned will be the last values stored, unless these parameters are requested after a DCL, in
which case unusable readings will be returned.
When in B0, normal electrometer readings will be sent. In a continuous trigger mode, readings
will be updated at the conversion rate (one reading every 360msec). In B1, readings will be tak-
en from consecutive data store locations, beginning with the oldest reading and progressing to
the newest reading until all readings currently stored have been read. Once all readings have
been requested, the unit will cycle back and begin again. These readings may be accessed even
if data store is still taking place.