Campbell Scientific CR23X Micrologger - Manual (Page 162)

SECTION 9. INPUT/OUTPUT INSTRUCTIONS
9-28
TABLE 9-10. Extended Vibrating Wire
Range Codes
Range Peak to Peak Volts Maximum
Code Required @ Max. Freq.* Frequency
1 2 mV 10 kHz
2 5 mV 20 kHz
3 20 mV 30 kHz
4 500 mV 100 kHz
PARAM DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions (Index (- - )
to skip repeat of
excitation)
02: 2 Range Code (Table 9-10)
03: 2 Single-ended channel
for first measurement
04: 2 EX CHAN
05: 4 Starting Frequency
(HZ)
06: 4 Ending Frequency (HZ)
07: 4 T (sweep, Units = 1
msec)
08: 4 N (Number of steps)
09: 4 Delay after excitation
before measurement
(Units = 0.01 sec)
10: 4 CYCLES to measure
11: 4 DELAY between reps
(Units = 0.01 sec)
12: 4 First Input Location
13: FP Multiplier
14: FP Offset
Input Locations Altered: 2 per repetition
*** 132 INPUT SETTLING TIME ***
Instruction P132 allows a user to change the
default 450
µ
s input voltage settling time for
Instructions P1, P2, P5, P6, P7, P9, P11, P13,
and P14. Measurement errors will result if
insufficient input settling time exists for a given
sensor and cable length (see Section 13.3). The
minimum allowable settling time for P132 is 100
µ
s for all input ranges except the
±
10 mV range,
in which 200
µ
s is the minimum. The maximum
allowable settling time is 6 ms. An entry of 0.0000
ms results in the default 450
µ
s input settling
time. High-output impedance (> 1 k
Ω
) sensors
and / or long cable lengths may require more
than the 450
µ
s default settling time. Low-output
impedance sensors and / or short cable lengths
may require less settling time. A single P132
instruction in the datalogger program will change
all applicable default settling times. Multiple
P132 instructions in a datalogger program will
cause settling time changes for the analog
measurement instructions following each P132.
Shortened settling times for the P10 and P17
instruction will degrade the measurement
accuracy, while longer times will increase the
time required to perform the instructions. A P132
within a scan does not over-ride the settling
times in the P4 and P8 instruction; instead it adds
to this time. If P132 is used in the program, P4,
P8, P10, and P17 Instructions should be
preceeded by a P132 to set the settling time
back to the desired 450
µ
s (time 0.0000).
Performing P132 instructions within a scan
increases the time to execute the scan by 0.13
ms per P132 instruction. This needs to be
considered when using the P132 instruction to
reduce the time required to complete a scan.
P132 in Table 1 will not affect measurements in
Table 2. The reverse is also true.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: FP milliseconds
Minimum = 0.2 for X1
Range codes, else
Minimum range is 0.1.
Maximum = 6.0 ms.
0 = default = 450
milliseconds
Input Locations Altered = 0
*** 133 Continuous Analog Out ***
Sets a continuous analog output port to a
voltage level specified in an input location. The
analog output degrades approximately 0.17mV
every 7 seconds requiring the instruction to be
periodically repeated to maintain a given output
accuracy.
mA mA
Port Source Sink
Option Description (+V) (-V)
01 - 02 CAO1 & CAO2 15 5
11 - 12 CAO1 & CAO2 15 15
with Boost