Programmable Logic Control - Campbell CR300 Series Product Manual

When in sleep mode, hardware is configured to detect activity and wake up. Sleep mode may
lose the first character of the incoming data stream. PakBus takes this into consideration in the
"ring packets" that are preceded with extra sync bytes at the start of the packet.
leaves the interface powered-up, so no incoming bytes are lost. See the CRBasic Editor help for
detailed instruction information and program examples:
https://help.campbellsci.com/crbasic/cr300/.
When the data logger has data to send via RS-232, if the data is not a response to a received
packet, such as sending a beacon, it will power up the interface, send the data, and return to
sleep mode without a 40 second timeout.
See also Wiring panel and terminal functions

2.5 Programmable logic control

The data logger can control instruments and devices such as:
Controlling cellular modem or GPS receiver to conserve power.
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Triggering a water sampler to collect a sample.
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Triggering a camera to take a picture.
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Activating an audio or visual alarm.
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Moving a head gate to regulate water flows in a canal system.
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Controlling pH dosing and aeration for water quality purposes.
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Controlling a gas analyzer to stop operation when temperature is too low.
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Controlling irrigation scheduling.
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Control decisions can be based on time, an event, or a measured condition. Controlled devices
can be physically connected to C, VX, SE1 -SE4, P_SW, or SW12 terminals. Short Cut has
provisions for simple on/off control. Control modules and relay drivers are available to expand
and augment data logger control capacity.
C terminals are selectable as binary inputs, control outputs, or communication ports. These
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terminals can be set low (0 VDC) or high (5 VDC) using the
instructions. See the CRBasic Editor help for detailed instruction information and program
examples: https://help.campbellsci.com/crbasic/cr300/.
driven interrupts, asynchronous communications and SDI-12 communications. A C terminal
configured for digital I/O is normally used to operate an external relay-driver circuit
because the terminal itself has limited drive capacity.
VX terminals can be set low or high using the
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more information on these instructions, see the CRBasic help.
SW12 terminals can be set low (0 V) or high (12 V) using the
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CRBasic help for more information).
(p. 5).
PortSet()
Other functions include device-
PortSet()
or
SW12()
2. Wiring panel and terminal functions
SerialOpen()
WriteIO()
or
SWVX()
instruction. For
instruction (see the
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