Period Averaging - Details; Digital Input/Ouput - Details; Communication - Details; Communication Ports - Campbell CR300 Series Operator's Manual

CR300-Series Datalogger
6.3 Period Averaging – Details
6.4 Digital Input/Ouput – Details
6.5 Communication – Details

6.5.1 Communication Ports

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Pulse input terminals and the input types they can measure are shown in
TABLE 6-3.
TABLE 6-3. Pulse Measurement Input Types, Terminals,
Input Type Pulse Input Terminal
High-frequency
Low-level AC
Switch-closure
SE terminals 1-4 on the CR300 are also configurable for measuring the period
of a digital signal. The specified number of cycles is timed with a resolution of
13 ns, making the resolution of the period measurement 13 ns divided by the
number of cycles chosen. The signal transition threshold is 2.5 V.
Period-average measurements use a high-frequency digital clock to measure
time differences between signal transitions, whereas pulse-count measurements
simply accumulate the number of counts. As a result, period-average
measurements offer much better frequency resolution per measurement
interval, as compared to pulse-count measurements.
Maximum frequency: 200 kHz
Resolution: 13 ns ÷ number of cycles to be measured
Terminals C1, C2, P_SW, and SE 1-4 can be configured for digital input or
output. As input terminals, they can measure the state, low (0 V) or high
(threshold 3.3 V), of an input. As output terminals, they can be set low (0 V) or
high (SE 1-4 and P_SW to 3.3 V, and C1-C2 to 5 V). With limited drive
capacity, digital output terminals are normally used to operate external relay-
driver circuits. Drive current and high-state voltage levels vary between
terminals. See TABLE 7-6, Digital I/O Voltage Levels
Pulse-width modulation can be done on terminals SE1 – SE4. See the PWM()
instruction in CRBasic Editor Help for more information.
The CR300 is equipped with hardware ports that allow communication with
other devices and networks, such as:
• PC
• Smart sensors
and Data Options
Data Option
SE 1-4
C1-C2
P_SW
P_LL
Running average of
P_LL
P_SW
C1-C2
(p. 47)
Counts
Frequency
frequency
.