Rice Lake 720i Programmable Indicator/Controller - Installation Manual - Manual (Page 71)

Setpoints 65
8.0 Setpoints
Note
Directions in this chapter require the batching
version of software (720i batching).
The 720i indicator provides 32 configurable setpoints
for control of both indicator and external equipment
functions. Setpoints can be configured to perform
actions or functions based on specified parameter
conditions. Parameters associated with various setpoint
kinds can, for example, be configured to perform
functions (print, tare, accumulate), to change the state
of a digital output controlling indicator or external
equipment functions, or to make conditional decisions.
Note
Weight-based setpoints are tripped by values
specified in primary units only.
8.1 Batch and Continuous Setpoints
720i setpoints can be either continuous or batch
setpoints.
Continuous setpoints are free-running: the
indicator constantly monitors the condition of
free-running setpoints at each A/D update. The
specified setpoint action or function is performed
when the designated setpoint parameter conditions
are met. A digital output or function assigned to a
free-running setpoint continuously changes state,
becoming active or inactive, as defined by the
setpoint parameters.
Batch setpoints are active one at a time, in an
ordered sequence. The 720i can use setpoints to
control up to 32 separate batch processing steps.
A digital output associated with a batch setpoint is
active until the setpoint condition is met, then
latched for the remainder of the batch sequence.
To use batch setpoints, you must activate the
BATCHNG parameter on the SETPTS menu. This
parameter defines whether a batch sequence is
automatic or manual. AUTO sequences repeat
continuously, while MANUAL sequences require a
BATSTRT signal. The BATSTRT signal can be
initiated by a digital input, serial command, or
Batch Start softkey.
For setpoint kinds that can be used as either
continuous or batch setpoints, the BATCH
parameter must also be set ON. (Setpoint kinds that
can only be used as batch setpoints do not require
the BATCH parameter.) If the setpoint is defined
but the BATCH parameter is off, the setpoint
operates as a continuous setpoint, even during
batch sequences.
Note
In applications that contain both batch setpoint
routines and continuous setpoints, continuous
setpoints should be kept separate from the
batch sequence. This is especially true when
using CONCUR or TIMER setpoints to perform actions or
functions based on the batch sequence. CONCUR and
TIMER setpoints should not be included in the referenced
START and END setpoint sequence.
Kind Description Batch Continuous
OFF Setpoint turned off/ignored.
GROSS Gross setpoint. Performs functions based on the gross weight. The target weight
entered is considered a positive gross weight. X X
NET Net setpoint. Performs functions based on the net weight. The target weight
entered is considered a positive net weight value. X X
–GROSS Negative gross weight. Performs functions based on the gross weight. The target
weight entered is considered a negative gross weight. X X
–NET Negative net weight. Performs functions based on the net weight. The target
weight entered is considered a negative net weight value. X X
ACCUM Accumulate setpoint. Compares the value of the setpoint to the source scale
accumulator. The accumulator setpoint is satisfied when the value of the source
scale accumulator meets the value and conditions of the accumulator setpoint. X X
ROC Rate-of-change setpoint. Performs functions based on the rate-of-change (ROC)
value. X X
+REL Positive relative setpoint. Performs functions based on a specified value above a
referenced setpoint, using the same weight mode as the referenced setpoint. X X
–REL Negative relative setpoint. Performs functions based on a specified value below a
referenced setpoint, using the same weight mode as the referenced setpoint. X X
Table 8-1. Setpoint Kinds