4.6
Valve control
Control of the ejector pulse
The ejector pulse is controlled via the output bit "ejector pulse". The ejection signal has a dominating
effect and stops the vacuum generation immediately. After removing the ejection signal, the valve
returns to its initial position.
If the parameter "Interlock ejector pulse" is activated and no load voltage (U
val
) is present, the ejector
signal is ignored. Instead, the valve remains in the vacuum position (incl. air-saving function) or in the
normal position.
4.7
Power ejector pulse (VABF-...-AP)
So that less air escapes unused through the silencer when the vacuum generator is pressurised, the
exhaust air duct is closed with a shut-off piston during the ejection pulse. To protect the vacuum gen-
erator from dirt particles, an additional strainer is installed to filter the air sucked in.
NOTICE!
Destruction of the product due to overpressure
If the vacuum connection is tightly closed, overpressure can occur at the vacuum connection and des-
troy the pressure sensor.
•
Use power ejector pulse only in open vacuum systems.
Function
11
Festo — VABF-S4-...-CB-VH/VL-... — 2019-05
