F.W. Bell 7030, Инструкция по эксплуатации

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F.W. BELL Model 7030 Gauss/Tesla Meter Instruction Manual
7-40 Section 7 – Remote Operation
SCPI COMMANDS-
MEASUREMENT
COMMANDS
(Continued) MEASure#:FFLux?
This command is similar to the MEASure#:FLUX? command but can be
used to acquire new flux density readings at a much faster rate.
However, the returned values are not be as precise or accurate. For
example, if the presently displayed reading is -2.87347 T, this command
may return –2.872 T.
This command uses the same information that is used to construct the
corrected analog output, therefore the accuracy is the same as specified
for the corrected analog output. The corrected analog output must be
turned on to use this command. Use the ANALOG OUT menu or
OUTPut# commands to enable the output. The analog output voltage
range has no affect on the returned value, so it can be set to any desired
level. However, the type of output selected, whether “raw” or “rms”, will
affect the value returned by this command.
For example assume that the probe is measuring a 50 Hz sinusoidal field
with an rms value of 2.5 gauss. If the corrected analog output is
configured for “rms” then the returned value will be 2.5. If the output is
configured for “raw” then the value returned will be one point of the 50 Hz
waveform, which can range from 0 to
±
3.535 gauss (the peak value of a
2.5 gauss rms signal is about 3.535 gauss).
The rate at which new flux density readings can be acquired using this
command is roughly 100 per second, but the speed of the
communications port can degrade this.
For example, suppose the abbreviated version of the command is issued,
such as “MEAS1:FFL?<lf>. If the RS-232 port is used at a baud rate of
9600, a character length of 7, one stop bit and no parity, it would take at
minimum about 0.011 seconds to transmit the command. If the meter
returns a value of “–22.34;<lf>”, this would take about 0.008 seconds.
There is also a small amount of time needed for the meter to interpret the
command and acquire a reading. So, let’s assume a total of 0.02
seconds for one transaction. This would limit the number of readings to
50 per second, best case. Use a higher baud rate or the GPIB interface
to increase the speed.
:MEASure#:TEMPerature?
The latest temperature reading from a temperature-compensated Hall
probe is placed in the output queue. The meaning of this value depends
upon the currently selected unit of measure (celsius, kelvin or fahrenheit).
For instance the value 45.3 could mean 45.3
°
F or 45.3
°
C.
:MEASure#:TIMe?
The latest frequency or period measurement of the flux density signal is
placed in the output queue. The meaning of this value depends upon the
currently selected unit of measure (seconds or hertz).