Fluid Components International FS10A - Manual (Page 20)

FS10 Series
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The hysteresis may be applied above the trip point or below the trip point. As an example, if set above the trip-point in an application requir-
ing low flow detection, the relay will change state as the signal falls below the trip point, but will not reset until it reaches the trip-point
value plus the added hysteresis value. The default setting is hysteresis above the trip-point and set at 2% of trip-point value. If changes are
required to the default, see how the hysteresis is applied in Function 8 and set the value in Function 9. Any value hysteresis may be applied
through the RS232 PC or command line interface. The button functions are limited to settings between 0% and 10% in 1% increments.
Time Delay (Function 10 or 11)
A time delay may be applied to the trip-point in one of two ways. The time delay may be applied to activate (Function 10) the relay after the
trip-point has been reached, or may be applied to de-activate (Function 11) the relay after the trip-point has been reached. The time starts
as the trip-point is reached and counts down as long as the trip-point value is retained. The relay then changes state. If the trip-point was
reached, but not maintained during this period, the time delay resets and the relay does not change state. The default value is zero seconds
and may be increased in 1-second increments up to 10 seconds with the buttons (time delays considerably higher are achievable through the
RS232 interface >65k secs).
Function 10 operation (relay change of state is delayed this amount [sec.] after signal reaches trip-point) is normally used in applications
where false trips may occur due to turbulent or cyclic flow action or in wet dry applications where splashing during vessel filling, for example,
may cause premature actuation. Proper setting of the time delay in this mode can be very effective in preventing problematic nuisance trips.
Function 11 operation (relay change of state is delayed this amount [sec] after signal leaves trip-point) may also be used in cyclic flow condi-
tions. Another possible use may be to fill a vessel after a low level is reached. For example, the level reaches the low level trip-point; the
relay immediately changes state and is set to actuate a solenoid valve that begins the filling action. A time delay may be set that corresponds
to the time needed to fill the vessel.
Important: The time delay function is dependent on the Failsafe Position (Function 3). Therefore, select the proper mode of
delay based on relay being activated in normal operation and de-activated in the alarm condition. These selections
are likely to be different when alarm settings are for low flow (or dry) verses high flow (or wet) applications.
Alarm Simulation (Function 12)
This function is used to force the output to the highest or lowest value, resulting in a change of relay state as well. Alarm simulation may be
useful in testing the system in which the FS10 is installed.
Keypad Lockout (Function 13)
This function changes the time required to depress the two buttons to enter into the set-up mode from the default 3 seconds to 10 seconds
(and back). Total button lockout may be achieved through the digital interface program via the RS232 connection.
Filter Setting (Function 14)
A filter is applied to the raw input signal (delta R). It is used to smooth the output against fluctuating or turbulent flow conditions. The range
of the filter setting is 3-100. The default setting is 18 and reduces the time response by < 2 seconds. A setting of 100 will provide the maxi-
mum dampening of the signal and decreases the response time approximately 10 seconds. Settings from 3 to 100 may be applied using the
RS232 PC interface or command line interface. The buttons permit changes of values 3, 18, 30, 50 and 100 only.
Save to Bank (Function 15)
Set-up configurations may be saved to bank 7. After the FS10 is field configured, storing the parameter settings to bank 7 is performed in this
function.