Section 8. Operation
396
First Six Values of Settling Time Data
TIMESTAMP
REC
PT(1)
PT(2)
PT(3)
PT(4)
PT(5)
PT(6)
Smp
Smp
Smp
Smp
Smp
Smp
1/3/2000 23:34
0
0.03638599
0.03901386
0.04022673
0.04042887
0.04103531
0.04123745
1/3/2000 23:34
1
0.03658813
0.03921601
0.04002459
0.04042887
0.04103531
0.0414396
1/3/2000 23:34
2
0.03638599
0.03941815
0.04002459
0.04063102
0.04042887
0.04123745
1/3/2000 23:34
3
0.03658813
0.03941815
0.03982244
0.04042887
0.04103531
0.04103531
1/3/2000 23:34
4
0.03679027
0.03921601
0.04022673
0.04063102
0.04063102
0.04083316
Open-Input Detect
Note
The information in this section is highly technical. It is not
necessary for the routine operation of the CR6.
Summary
• An option to detect an open-input, such as a broken sensor or loose
connection, is available in the CR6.
• The option is selected by appending a
C
to the
Range
code.
• Using this option, the result of a measurement on an open connection
will be
NAN
(not a number).
A useful option available to single-ended and differential measurements is the
detection of open inputs due to a broken or disconnected sensor wire. This
prevents otherwise undetectable measurement errors. Range codes appended
with
C
enable open-input detect for all input ranges. See
TABLE: Analog Input
Voltage Ranges and Options
(p. 416).
Appending the
Range
code with a
C
results in a 50 µs internal connection of the
V+ input of the PGIA to a large over-voltage. The V– input is connected to
ground. Upon disconnecting the inputs, the true input signal is allowed to settle
and the measurement is made normally. If the associated sensor is connected, the
signal voltage is measured. If the input is open (floating), the measurement will
over-range since the injected over-voltage will still be present on the input, with
NAN
as the result.
Range codes and applicable over-voltage magnitudes are found in
TABLE: Range
Code Option C Over-Voltages
(p. 397).
The
C
option may not work, or may not work well, in the following applications:
•
If the input is not a truly open circuit, such as might occur on a wet cut
cable end, the open circuit may not be detected because the input
capacitor discharges through external leakage to ground to a normal
voltage within the settling time of the measurement. This problem is
worse when a long settling time is selected, as more time is given for the
input capacitors to discharge to a "normal" level.
Summary of Contents for CR6 Series
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Page 76: ...Section 5 Overview 76 FIGURE 20 Half Bridge Wiring Example Wind Vane Potentiometer ...
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Page 459: ...Section 8 Operation 459 FIGURE 106 Vibrating Wire Sensor Calibration Report ...
Page 535: ...Section 8 Operation 535 8 11 2 Data Display FIGURE 121 CR1000KD Displaying Data ...
Page 537: ...Section 8 Operation 537 FIGURE 123 CR1000KD Real Time Custom ...
Page 538: ...Section 8 Operation 538 8 11 2 3 Final Storage Data FIGURE 124 CR1000KD Final Storage Data ...
Page 539: ...Section 8 Operation 539 8 11 3 Run Stop Program FIGURE 125 CR1000KD Run Stop Program ...
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