Section 4. Sensor Support
45
When a pulse channel is configured for pulse input mode, an internal 100 k
Ω
pull-up resistor to +5 Volt on the P_SW input is automatically employed. This
pull-up resistor accommodates open-collector (open-drain) output devices for
high-frequency input. An external 100 k
Ω
pull-up resistor connecting
to P_LL, C1, or C2 must be added to perform pulse counting on any of those
channels (See
Multiple Switch Closure Measurements
p. 112).
The maximum input voltage on P_SW is 4 volts. For C1 and C2 the maximum
input voltage is 6.5 volts.
4.4.1.2
Low-Level AC (P_LL)
Rotating magnetic pickup sensors commonly generate AC output voltages
ranging from millivolts at low rotational speeds to several volts at high
rotational speeds. Channel P_LL contains internal signal conditioning hardware
for measuring low-level AC output sensors. P_LL measure signals ranging
from 20 mV RMS (±28 mV peak) to 14 V RMS (±20 V peak). Internal AC
coupling is incorporated in the low-level AC hardware to eliminate DC offset
voltages of up to ±0.5 V.
4.4.2
Pulse Input on Digital I/O Channels C1–C2
Read More! Review digital I/O channel specifications in
Specifications
p. 35.
Review pulse counter programming in CRBASIC Help for the PulseCount ()
instruction.
Digital I/O channels C1 – C2 can be configured to measure pulse input signals.
Pulse input signals require external 100 k
Ω
pull-up resistors to be connected
between and the control ports. Maximum input voltage level is 6.5 V.
If pulse inputs greater than +6.5 V need to be measured, external signal
conditioning must employed. Contact Campbell Scientific for further
information.
Low-level AC signals cannot be measured directly on channels C1 – C2.
4.5 Period Averaging Measurements
The CR200(X) can measure the period of a signal on any single-ended analog
input channel (SE 1 - 5). The specified number of cycles are timed with a
resolution of 70 ns, making the resolution of the period measurement 70 ns
divided by the number of cycles chosen.
Cycles are counted as the input voltage transitions from less than 0.9 volts to
more than 2.1 volts. The maximum input voltage must be less than 4 volts. The
maximum frequency that can be detected is 150 kHz.
Summary of Contents for CR200
Page 32: ...Section 2 Quickstart Tutorial 22 ...
Page 45: ...Section 3 Overview 35 3 3 Specifications ...
Page 46: ...Section 3 Overview 36 ...
Page 58: ...Section 4 Sensor Support 48 ...
Page 62: ...Section 5 Measurement and Control Peripherals 52 ...
Page 78: ...Section 8 CR200 X Configuration 68 ...
Page 102: ...Section 9 Programming 92 ...
Page 138: ...Section 11 Programming Resource Library 128 ...
Page 156: ...Section 16 Support Software 146 ...
Page 160: ...Section 17 Care and Maintenance 150 ...
Page 167: ...Section 18 Troubleshooting 157 18 3 3 2 Charging Circuit Test Solar Panel ...
Page 168: ...Section 18 Troubleshooting 158 18 3 3 3 Charging Circuit Test Transformer ...
Page 169: ...Section 18 Troubleshooting 159 18 3 3 4 Adjusting Charging Circuit Voltage ...
Page 170: ...Section 18 Troubleshooting 160 ...
Page 184: ...Appendix A Glossary 14 ...
Page 190: ...Appendix B Status Table and Settings 20 ...
Page 192: ...Appendix C Serial Port Pin Outs 22 ...
Page 211: ......