VOFA−...
Festo VOFA−... 1004NH English
62
Fig.10 shows the pneumatic and electric switch−off characteristics at the control
block with PNP proximity sensors and without resistive load.
Throughinterrogation (resistive load) of the proximity sensor, the switching times
can be extended by max. 2ms. With use of NPN proximity sensors, the signal
characteristics are reversed, i.e.dropping instead of rising.
Process during switch−off:
At the time t=0, voltage to both coils is switched off. After approx.56ms,
pneumatic actuation changes from port (4) to (2), and the proximity sensors report
that the piston spools of the solenoid valves have reached die neutral position
after a total of approx.60ms.
p2
p4
U2
U1
1
p2 = pressure on port (2)
2
p4 = pressure on port (4)
3
U1 = signal voltage on proximity sensorE1
4
U2 = signal voltage on proximity sensorE2
Fig.10: Path−step diagram with signal sequence during switch−off
of the control block
(diagramshowsmeasurements with the PNP proximity switch without resistive load)
Summary of Contents for VOFA-B26-T52-M Series
Page 26: ...VOFA Festo VOFA 1004NH Deutsch 26 Bild 11 Funktionstest Schritte 1 bis 4...
Page 27: ...VOFA Festo VOFA 1004NH Deutsch 27 Bild 12 Funktionstest Schritte 5 bis 7...
Page 64: ...VOFA Festo VOFA 1004NH English 64 Fig 11 Function test steps 1 to 4...
Page 65: ...VOFA Festo VOFA 1004NH English 65 Fig 12 Function test steps 5 to 7...
