Dynalco SWT-1000 Speed Switch/Transmitter - Manual (Page 20)

Operating Instructions SWT-1000 DYNALCO
SWT-1000.r2.0609 18
8.2.2 Signal Failure
In the event of a sudden loss of a good signal, no positive edge arrives to complete the
measurement or start a new one. Once the minimum measurement time (Fixtime) has lapsed the
unit waits for twice the last measurement period following which half the last measured speed is
assumed. If the signal remains missing then the measurement approaches zero.
8.3 Functions
8.3.1 Limits and Window Function
Since the upper and lower sets points are freely selectable a large hysteresis may be set. If that is
not necessary we recommend setting a 10% hysteresis.
The Window function allows an Exclusive OR combination of Limits 1 and 2, whereby the status of
both limits is first determined (including any inversion) and a subsequent ExOR comparison
executed.
As soon as Relay assignment is the relay behaves as follows:
• With identical limit modes (both Normal or both Inverse) the relay is activated when the
measured value lies between the Limit 1 and 2 settings.
• If different modes are set (one Normal and the other Inverse) the relay is deactivated when
the measured value is between Limts 1 and 2.
8.3.2 Parameter Sets A and B
The SWT-1000 has 2 parameter sets available that define the relay assignment. Parameter set A
would normally be used. If another parameter set is needed, e.g. for test purposes, the binary
input may be used to change to parameter set B. The transfer from parameter set B to parameter
set A may be delayed in the range 0 to 2000 seconds. Transferring from A to B is however
immediate and not affected by this setting.
To be able to select parameter sets using the binary input, Relay control - Selection of Actuator
must be appropriately set.
Binary input condition Selected Parameter set
High (5V) “normal“ A
Low (0V) “connected to 0V“ B
8.3.3 Relay Hold Function
A latch function may be assigned to the relay. By selecting the
relay is activated once the assigned limit is active and remains held even if the input frequency
would no longer cause a trip. By selecting , the deactivared
state of the relay is held. The latched status may be reset by cycling power or via the binary input,
whereby the binary input must be activated as per the configuration (0V or 5V) for between 0.1
and 0.3 seconds.
8.3.4 Push-Button
The front panel push button internally connects the binary input to 0VS thus generating a logic 0.