Campbell Scientific CR9000X Measurement and Control System - Manual (Page 269)

Section 7. Measurement Instructions
7-45
Parameter Enter VOLTFILT PARAMETERS
Dest
Variable,Array
The Variable to store the results of the instruction. When Reps are used the results are stored in an
array with the variable name. An array must be dimensioned to have elements for all Reps.
Reps
Constant
The number of times to repeat the measurement on subsequent CR9052 channels. .
Range The voltage range for the measurement. The CR9052 normally replaces out-of-range
measurements with not-a-number (NaN) which is displayed in RTDaq's real time windows as
Range? . Users may choose to have out-of-range measurements to be replaced by the analog-to-
digital converter saturation value with a special code in FiltOption.
Constant Alpha
Code Numeric
Code Voltage
Range Module Excitation
Board Supported
mV5000 0 ± 5000 mV CR9052DC, CR9052IEPE
mV1000 1 ± 1000 mV CR9052DC, CR9052IEPE
mV200 4 ± 200 mV CR9052DC
mV50 5 ± 50 mV CR9052DC
mV20 6 ± 20 mV CR9052DC
Fslot
Constant
The number of the slot that holds the CR9052 Module to be used for the measurement.
Chan
Constant
The CR9052 channel number on which to make the first measurement. When Reps are used,
subsequent measurements will be automatically made on the following differential channels.
FiltOption
Constant The sample ratio for the measurement (how many measurements are made within one cycle of the
highest frequency in the pass band). The sample ratio determines the top of the pass-band (F
PASS
)
and the beginning of the stop-band (F
STOP
) of the anti-aliasing low-pass filter relative the sample
rate (F
SAMPLE
). The sample rate is the inverse of the scan interval in the CRBASIC program.
FiltOption must be the same for all channels of a single CR9052 Filter Module. Out-of-range
measurements may be replaced by the analog-to-digital converter saturation value by adding 1000
to the FiltOption codes shown below.
NumericCode Sampling Ratio F
PASS
F
STOP
2 2.5 F
SAMPLE
/2.5 F
SAMPLE
/2.01
5 5 F
SAMPLE
/5 F
SAMPLE
/3.37
10 10 F
SAMPLE
/10 F
SAMPLE
/5.08
20 20 F
SAMPLE
/20 F
SAMPLE
/6.81
1* 2.155 23.2 Khz 26.8 kHz
* Option 1 has no additional filtering beyond the CR9052DC analog front-end and the sigma-delta
A/D converter, thus freeing the CR9052DC on-board digital signal processor for additional
processing. F
SAMPLE
must be 50 kHz to use this filter option.
Excitation
Constant
The continuous, dc, output for the excitation channel(s). If Reps is greater than one, then the same
excitation will be output on sequential excitation channels.
Numeric Code Alpha Code Output Level IEPE Freq. Response
CR9052IEPE 900 (905) None None τ = 0.5 Sec ( τ = 5.0 Sec)
CR9052IEPE 605 None Constant 6 mA 0.3 Hz to 20 kHz ( τ = 5.0 Sec)
CR9052IEPE 405 None Constant 4 mA 0.3 Hz to 20 kHz ( τ = 5.0 Sec)
CR9052IEPE 205 None Constant 2 mA 0.3 Hz to 20 kHz ( τ = 5.0 Sec)
CR9052IEPE 600 None Constant 6 mA 3.0 Hz to 20 kHz ( τ = 0.5 Sec)
CR9052IEPE 400 None Constant 4 mA 3.0 Hz to 20 kHz ( τ = 0.5 Sec)
CR9052IEPE 200 None Constant 2 mA 3.0 Hz to 20 kHz ( τ = 0.5 Sec)
CR9052DC 7 V10 Constant 10 V DC N/A
CR9052DC 5 None Constant 5 V DC N/A
CR9052DC 2 None Constant 10 mA N/A
CR9052DC 1 None None N/A
Mult, Offset
Constant,Variable,
Array, Expression
A multiplier and offset by which to scale the measurement. A multiplier of one and an offset of 0
will return the measurement in millivolts.