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12 using the switched 12 v to power sensors – Campbell Scientific CR10X Measurement and Control System User Manual

Page 130

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SECTION 8. PROCESSING AND PROGRAM CONTROL EXAMPLES

8-22

14:

Scaling Array (A*Loc+B) (P53)
1:

8

Start Loc [ _________ ]

2:

4

A1

3:

0

B1

4:

6

A2

5:

0

B2

6:

9

A3

7:

0

B3

8:

11

A4

9:

0

B4

15:

Z=F (P30)
1:

0

F

2:

0

Exponent of 10

3:

12

Z Loc [ _________ ]

16:

Beginning of Loop (P87)
1:

0

Delay

2:

4

Loop Count

17:

Z=X+Y (P33)
1:

8--

X Loc [ _________ ]

2:

12

Y Loc [ _________ ]

3:

12

Z Loc [ _________ ]

18:

End (P95)

19:

Z=X*F (P37)
1:

12

X Loc [ _________ ]

2:

1

F

3:

284--

Z Loc [ _________ ]

20:

End (P95)

21:

End (P95)

End Program

22:

P

End Table 3

*

A

Mode 10 Memory Allocation

01: 2500

Input Locations

02:

270

Intermediate Locations

8.12 USING THE SWITCHED 12 V TO

POWER SENSORS

In this example, it is required to measure air
temperature at two levels at a remote site where
AC power is not available. The station is
powered with a 12 V battery that is trickle
charged by a solar panel. Two 12 VDC
aspirated thermocouples (ASPTC) are used
measure air temperature. To minimize the
current drain of the ASPTCs, the fans are
turned on 20 seconds before the CR10X
measures the thermocouples. Immediately
after the thermocouple measurements are
made the fans are turned off.

The Switched 12 V terminal on the CR10X
wiring panel is used to power the ASPTCs. The
maximum amount of current that the Switched
12 V terminal can source is 600 mA. Each
ASPTC draws 140 mA, for a total ASPTC
current requirement of 280 mA. The Switched
12 V terminal is operated with Control port 1.
Connect a short jumper wire between Control
port 1 and the Switched 12 V Control (see
Figure 8.12-1).