Standard Differential Valve Logic - Scanivalve DSA5000 Series Operation And Service Manual

Appendix

Standard Differential Valve Logic

Standard or common differential builds. This includes single (Px) and standard differential dual range (DR) units.
Dual range units will have two CAL and REF ports, one for each group of pressure ranges (L for channels 1-8, H for channels
9-16). The valve operates the same, however the CAL/REF ports are only common to the label group of channels.
( + )
Transducer
( - )
Figure C.1 - Measurement (PX) Mode
Standard Differential (including Dual Range) Valve Logic
Measurement (Px) Mode
( + )
Transducer
( - )
Figure C.3 - Purge (PRG) Mode
Standard Differential (including Dual Range) Valve Logic
Purge (PRG) Mode
PRGCTL
CTL1
CTL2
PRGCTL
CTL1
CTL2
( + )
Transducer
( - )
Figure C.2 - Calibrate (CAL) Mode
Standard Differential (including Dual Range) Valve Logic
Calibrate (CAL) Mode
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( + )
Transducer
( - )
Figure C.4 - Isolate (ISO) Mode
Standard Differential (including Dual Range) Valve Logic
Note: In isolate only mode, the current pressure between the CTL1 valve
and the Transducer ( + ) will be trapped. Changes in temperature or eleva-
tion can increase or decrease this pressure which may cause overpressure.
Note: While the input is blocked, the REF is still open to the negative side
of the transducer. This could result in a differential overpressure.
94
94
PRGCTL
CTL1
CTL2
PRGCTL
CTL1
CTL2
Isolate (ISO) Mode
DSA5000
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