Controlled Venting; Stop Speed Reading - Agilent Technologies TwisTorr Medium-TMP Rack User Manual

Technical Information

Controlled Venting

This function is automatically enabled when the Valve Operating Mode is ON
COMMAND (for Manual Venting) or AUTO PUMP SPEED (for Pulsed Venting)
WIN 125 = 0 or 1.
This function activates only after STOP command, when the pump is slowing down.
During a controlled venting, the controller modulates the opening time of the vent
valve in order to decrease the pump rotational speed. The controller checks every
10 seconds the pump frequency and continues modulating the vent valve opening
process until the frequency is < 100 Hz.
Then the vent valve opens according to the delay (WIN 126) and the opening time
(WIN 147) set either via front panel or via serial communication.

Stop Speed Reading

This function allows the user to read the pump rotational frequency (window 232)
even after a stop command, during the braking.
The function can be activated/deactivated by serial communication (WIN 167). If
activated, all the related functions (set point output, programmable analog output –
if related to the frequency, ...) will follow the frequency reading.
The A-plus Software (optional) allows the operator to set all the programmable
NOTE
feature.
Agilent TwisTorr Medium-TMP Rack Controller User Manual 165