Campbell CR5000, Operator'S Manual

Page: 152 / 238

Section 7. Measurement Instructions
7-26
SW12
The SW12 instruction is used to set a Switched 12 volt supply high or low.
Syntax
SW12( State )
Remarks
The datalogger has a switched 12 volt output with two terminals. This switched
12 volts is used to provide a continuous 12 volt supply to external peripherals.
At room temperature the switched 12 volt supply can source 900 mA between
the SW-12 terminal and Ground. The State parameter indicates whether the
switched 12 volts is High (non-zero) or low (0).
The SW-12 supply is unregulated and can supply up to 900 mA
at 20C and up to 630 mA at 50C. A resettable polymeric fuse
protects against over-current. Reset is accomplished by removing
the load or turning off the SW-12 for several seconds.
SW12 Example
This example sets the switched 12 volt supply high at the beginning of each
scan, and low at the end of the program.
Const RATE = 500 'Scan interval number
Const RUNITS = 1 'Scan interval units (mSecs)
Const TBLINT1 = 200 'Table 1 interval number
Const UNITS1 = 1 'Table 1 interval units (mSecs)
Dim Tblk1( 1 ) 'Block #1 dimensioned source
Dim Tref 'Declare reference temperature variable
Public Flag( 8 ) 'Flag dimension
DataTable( TEST, Flag( 1 ), 1000 )
'Trigger, buffer of 1000 Records
DataInterval( 0, TBLINT1, UNITS1, 100 ) '200 mSecs, 100 lapses
Average( 1, Tblk1(), FP2, 0 ) 'Reps,Source,Res,Disable
EndTable 'End of table TEST
BeginProg
'Program begins here
Scan( RATE, RUNITS, 1, 0 ) 'Scan 500 (mSecs), no fast buffer
SW12( 1 ) 'Set SW12 high
PanelTemp( Tref., Integ ) 'PanelTemp
TCDiff( Tblk1(), 1, 1, 1, 1, Tref, 0, 20, 40, 1.8, 32 )
CallTable TEST 'Run Table TEST
SW12 ( 0 ) 'Set SW12 log
Next Scan 'Loop up for the next scan
EndProg 'Program ends here
NOTE