Section 5. Overview
98
The CR6 can control instruments and devices such as the following:
•
Wireless cellular modem to conserve power.
•
GPS receiver to conserve power.
•
Trigger a water sampler to collect a sample.
•
Trigger a camera to take a picture.
•
Activate an audio or visual alarm.
•
Move a head gate to regulate water flows in a canal system.
•
Control pH dosing and aeration for water quality purposes.
•
Control a gas analyzer to stop operation when temperature is too low.
•
Control irrigation scheduling.
Controlled devices can be physically connected to
C
terminals, usually through an
external relay driver, or the
SW12V
(p. 474)
terminal.
C
terminals can be set low (0
Vdc) or high (5 Vdc) using
PortSet()
or
WriteIO()
instructions. Control modules
are available to expand and augment CR6 control capacity. On / off and
proportional control modules are available. See appendix
PLC Control Modules
— List
(p. 655).
Tips for writing a control program:
•
Short Cut
programming wizard has provisions for simple on/off control.
•
PID control can be done with the CR6.
Control decisions can be based on time, an event, or a measured condition.
Example:
In the case of a cell modem, control is based on time. The modem requires 12 Vdc
power, so connect its power wire to the CR6
SW12V
terminal. The following
code snip turns the modem on for ten minutes at the top of the hour using the
TimeIntoInterval()
instruction embedded in an
If
/
Then
logic statement:
If
TimeIntoInterval
( 0,60,Min) Then
PortSet
(9,1)
'Port “9” is the
SW12V Port. Turn phone on.
If
TimeIntoInterval
(10,60,Min) Then
PortSet
(9,0)
'Turn phone
off.
TimeIsBetween()
returns
TRUE
if the CR6 real-time clock falls within the
specified range; otherwise, the function returns
FALSE
. Like
TimeIntoInterval()
,
TimeIsBetween()
is often embedded in an
If
/
Then
logic
statement, as shown in the following code snip.
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 ...
Page 80: ...Section 5 Overview 80 FIGURE 23 Pulse Input Wiring Example Anemometer ...
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Page 454: ...Section 8 Operation 454 FIGURE 104 Narrow Sweep High Noise ...
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 ...
Page 541: ...Section 8 Operation 541 FIGURE 127 CR1000KD File Edit ...
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