Agilent Technologies TV 401 NSF Bedienungshandbuch Seite 252

17 Technical Information
Interconnections
If a continuous signal is applied (pin 5 fixed at +24 V and pin 6 fixed
to ground) the pump speed is set to "Low Speed". The Low Speed
frequency is settable by window "117" (see para. "RS 232/RS 485
Communication Description").
PROGRAMMABLE ANALOG SIGNAL: this output signal is a voltage
(from 0 to 10 Vdc) linearly proportional to a reference quantity
(frequency or power) set by the user (0 V = 0 W or 0 Hz; 10 V = 150 W
or 1010 Hz). The default setting is the frequency.
FAULT: this open collector output signal is ON when a system fault
condition is detected.
PROGRAMMABLE SET POINT: this open collector output signal is
enabled when the reference quantity chosen (frequency, current or
time) is higher than the set threshold. The signal can be "high level
active" (that is the output is normally at 0 Vdc and becomes 24 Vdc
when activated), or "low level active" (that is the output is normally
at 24 Vdc and becomes 0 Vdc when activated). Moreover, if the
reference quantity is the frequency or the current drawn, it is
possible to set the hysteresis (in % of the threshold value) to avoid
bouncing.
The open collector output needs at least an external pull-up resistor (10 kΩ for
NOTE
example) between output and pin 9 (+24 Vdc) in order to "sec" a voltage switch.
For example with default values:
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reference quantity: frequency
threshold: 980 Hz
hysteresis: 2 %
activation type: "low level"
TV 401/301/21 NSF User Manual / 87-900-995-01 (C)