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Section 4. Sensor Support
38
4.1.3
Switched Unregulated (Nominal 12 Volt)
Voltage on the SW Battery terminal will change with CR200(X) supply voltage.
The CRBASIC instruction SWBatt () controls the SW Battery terminal.
Table 4.
Current Sourcing Limits
Terminal
Limit
VX1, VX2
25 mA @ 2.5V
10 mA @ 5V
SW Battery
< 900 mA @ 20°C
< 729 mA @ 40°C
< 630 mA @ 50°C
< 567 mA @ 60°C
< 400 mA @ 85°C
4.2 Voltage Measurement
4.2.1
Measurement Sequence
The first step in a voltage measurement is a calibration to measure the ground
offset. The calibration is performed once for each voltage measurement. The
CR200(X) measures analog voltages with a sample and hold analog to digital
(A/D) conversion. The A/D conversion is made with a 12-bit successive
approximation technique which resolves the signal voltage to one part in 4096
of the full scale 2.5 V range, which is 0.6 millivolts.
To reduce noise, 10 measurements are rapidly made and averaged to form the
result returned. The measurements that go into the average each take about 26
microseconds.
4.2.2
Measurement Accuracy
CR200(X) analog measurement error is calculated as
Error = Gain Error (%) + Offset Error
Gain error is expressed as ±% and is a function of input voltage and CR200(X)
temperature. It is minimized by factory calibration and increases with
component temperature and aging. Between -40°C and +50°C, gain error is
typically ±0.25% of the reading with a 1.2 millivolt offset. Worst case over that
same temperature range is ±1% of the reading with a 2.4 millivolt offset.
FIGURE. Voltage Measurement Accuracy (-40° to +50°C)
p. 40 illustrates that
as magnitude of input voltage decreases, measurement error decreases.
Содержание CR200
Страница 32: ...Section 2 Quickstart Tutorial 22 ...
Страница 45: ...Section 3 Overview 35 3 3 Specifications ...
Страница 46: ...Section 3 Overview 36 ...
Страница 58: ...Section 4 Sensor Support 48 ...
Страница 62: ...Section 5 Measurement and Control Peripherals 52 ...
Страница 78: ...Section 8 CR200 X Configuration 68 ...
Страница 102: ...Section 9 Programming 92 ...
Страница 138: ...Section 11 Programming Resource Library 128 ...
Страница 156: ...Section 16 Support Software 146 ...
Страница 160: ...Section 17 Care and Maintenance 150 ...
Страница 166: ...Section 18 Troubleshooting 156 18 3 3 Diagnosis and Fix Procedures 18 3 3 1 Battery Voltage Test ...
Страница 167: ...Section 18 Troubleshooting 157 18 3 3 2 Charging Circuit Test Solar Panel ...
Страница 168: ...Section 18 Troubleshooting 158 18 3 3 3 Charging Circuit Test Transformer ...
Страница 169: ...Section 18 Troubleshooting 159 18 3 3 4 Adjusting Charging Circuit Voltage ...
Страница 170: ...Section 18 Troubleshooting 160 ...
Страница 184: ...Appendix A Glossary 14 ...
Страница 190: ...Appendix B Status Table and Settings 20 ...
Страница 192: ...Appendix C Serial Port Pin Outs 22 ...
Страница 211: ......