Fairbanks H90-5200-A Digital Instrument - Manual (Page 18)

F. SETPOINT Operation And Programming
1. General Description, SETPOINT Modes
The Setpoints are used to control alarms, gate controls etc. that are furnished by the
customer. Setpoint operation is dependent on Gross or Net weight. The setpoint
outputs can only change state when the instrument is displaying Gross or Net weight.
If the instrument is not displaying Gross or Net weight, the setpoint outputs will revert
to their OFF state.
A setpoint output is ON if the Setpoint “Enable” LED is lighted AND the individual
Setpoint LED is ON.
Setpoint Mode Summary
Refer to Appendix VII for more information.
a. Individual (Single Feed) Setpoints Fast Feed Cutoff = SP - P
b. Paired (Dual Feed) Setpoints
Fast Feed Cutoff = SP - D - P Dribble Cutoff = SP - P
SP (Setpoint) = weight value desired at end of weighing operation
D (Dribble) = weight range at end of setpoint over which material flow
changes, usually from “fast” to “slow” feed
P (Preact) = weight value which is used to compensate for material in
suspension or other delays in control loop
There are six operating modes. “Mode 0” turns the setpoint option “OFF”. Two modes
are for setpoints only and three modes are for batching operations. In addition, a
zeroband operation in the Gross Mode only, up to capacity, is available in all modes, if
Setpoint 4 is available. The following sections explain each of the modes.
MODE 0- SETPOINTS OFF
The display shows “SP OFF”. The setpoint outputs are disabled.
MODE 1- SETPOINT MODE
The display shows “SP SP”. The setpoint mode is used for simple operations Where
the setpoint outputs are not directly controlling valves or gates and it is not desirable or
necessary to manually “start” and “stop” the setpoints.
Setpoint mode configures the outputs as simple “dumb” setpoints. When the absolute
value of the weight is less than the setpoint, the setpoint output is ON and when the
absolute value of the weight exceeds the setpoint, the setpoint output is OFF. The
setpoints are always active when the instrument is monitoring weight and the START,
TRIM, and STOP keys are not functional.
Up to 4 setpoints may be enabled and dribble, preact, discharge and zeroband options
are available. Some application examples are:
a. turning on a light to signal that a box has been filled to the proper weight.
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