750-00004 Parallax Inc, 750-00004 Datasheet - Page 24

• Manufacturer Part Number: 750-00004
• Description: POWER SUPPLY 24VDC 600MA
• Manufacturer: Parallax Inc

Specifications of 750-00004

• Form: Wall Mount (2 Prong)
• Voltage - Output Per Connector: 24VDC
• Current - Output: 600mA
• Polarization: Positive Center
• Cord Plug: 2.1mm I.D. x 5.5mm O.D. x 12mm Female
• Voltage - Input: 120VAC
• Power - Output: 14W
• Transformer Type: Linear, Unregulated
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Efficiency: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Since the output drivers for the Stamp PLC are "high-side" drivers, you must issue a LOW command to
energize an output, and likewise, you must issue a HIGH command to de-energize an output. The
Error_Handler subroutine checks the start code of each pump before starting it. If the pump is out of
commission, the other pump is started instead.
Each start routine functions the same way. If the pump is OFF, it attempts to start it. If the aux-contact
responds and, within 2 seconds, the flow responds, then the pump is considered to be running properly.
If either the flow indication or aux-contactor input fails, then the pump is flagged as out-of-commission
and de-energized.
StartA:
StartB:
Parallax, Inc. • Stamp PLC (#30064) • Version 1.8 • 12/29/2003
SELECT
ENDSELECT
RETURN
IF (pumpAStatus = 0) THEN
ENDIF
GOSUB Error_Handler
RETURN
IF (pumpBStatus = 0) THEN
ENDIF
GOSUB Error_Handler
RETURN
CASE
CASE
LOW PumpA
GOSUB GetDigitalInputs
IF auxContactA = 0 THEN
ELSE
ENDIF
LOW PumpB
GOSUB GetDigitalInputs
IF auxContactB = 0 THEN
ELSE
ENDIF
IF (PumpAStatus > 7) THEN GOSUB StartB
IF (PumpBStatus > 7) THEN GOSUB StartA
PAUSE 2000
GOSUB GetDigitalInputs
IF FlowA = 0 THEN
ELSE
ENDIF
pumpAStatus = 9
HIGH PumpA
PAUSE 2000
GOSUB GetDigitalInputs
IF (FlowB = 0) THEN
ELSE
ENDIF
pumpBStatus = 9
HIGH PumpB
pumpAStatus = 1
pumpAStatus = 8
HIGH PumpA
pumpBStatus = 1
pumpBStatus = 8
HIGH PumpB
startCode
1
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