Signal Description - Agilent Technologies TwisTorr 305-IC Manual De Instrucciones

8 Technical Information

Signal Description

Signal Description

Start/Stop: input signal to start or stop the pump. With the supplied cover connector
the START/STOP (+) signal is connected to the +24 Vdc pin and the START/STOP (-)
signal to the GROUND pin: in this condition the pump automatically starts as soon as
the controller recognises the input supply ("Plug & Pump").
Interlock: input signal to control the pump rotation. With the supplied cover connector
the interlock (+) signal is connected to the +24 Vdc pin and the interlock (-) signal to
the GROUND pin.
This input is used to provide a "soft start" to the pump. The soft start function lasts 15
minutes, but in case the pump for some reason (i.e. high volume vacuum chamber)
cannot reach full speed after those 15 minutes (or anytime you start the pump), then it
will try reaching full speed for an additional time.
By default this additional time is factory set to 15 minutes; this value (RunUpTime) is
selectable by a specific serial command (ref. to the Window Description chapter).
If full speed is not reached after that time an error condition sets in.
Speed setting: PWM input signal to set the pump speed. The PWM signal
characteristics must be the following:
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(1) The Speed Setting input is able to work also with a PWM signal having an
NOTE
amplitude equal to 13VDC or to 33VDC. In these conditions, the accuracy of
the speed setting is affected by a deviation value <1%.
(2) Due to the fact that the rotational target frequency value is adjustable via
serial command (refer to the "Windows meanings"), the input
condition in which the PWM duty cycle >75% will ensure a rotational
frequency equal to the one that has been set via the serial command;
the default factory setting for the rotational target frequency is 1010Hz.
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frequency: 100 Hz +/-20%
amplitude: +24VDC ± 10%
duty cycle range: from 25% to 75% (t
frequency varying linearly from 700 Hz to the target frequency value set
via serial command (default factory setting 1010 Hz). With duty cycle <25%
rotational frequency = 700 Hz, duty cycle >75% rotational frequency = target
frequency value (deviation value <0.25%).
TwisTorr 305-IC User Manual / 87-901-058-01 (A.00)
/T) corresponding to a rotational
off