EOS ProControl 2 plus Series User Manual

ProControl User’s Manual v2.2X
4 \8100\0074_1017
Active State
Central to the use of control on the Series 2
plus
is the concept of Active State. Each
input on the ProControl receives certain signals from a sensor which constitute
" normal# operation and other signals which constitute an exception to normal
operation.
A digital input can monitor only two states, ON or OFF (alternatively, CLOSED or
OPEN). The Active State would be the state in which the controller would respond
to the digital input, and perform certain actions or generate an alarm. For example,
if a high level float switch in a tank is tripped (turned ON) by rising fluid level, we
can say that its Active State
correlates to a situation in which the fluid level is high.
The active state of the float switch could cause the Series 2
plus
to trigger an alarm,
turn off a pump, or initiate some other action. The Series 2
plus
can be set up so that
either ON or OFF is the active state.
An analog input sensor can take on many states (or values) between the minimum
and maximum of its measurement range. The ProControl operator, however, can
set two threshold values which divide the total input span into two functional
regions. These threshold values are more commonly called the Low Alarm Limit
and the High Alarm Limit, although on the Series 2
plus
these thresholds are
somewhat more flexible in use than those names imply. An analog input which has
transcended either its Low Alarm Limit or High Alarm Limit is said to be in its
active state.
EAS WAS
0 psi
10 psi
Low
High
6
4
Figure 1. Active State
For instance, consider an analog input sensor which measures
pressure from 0 to 10 PSI. The system operator could set the low
limit to 4 PSI and the high limit to 6 PSI. In this case the Active
State would usually be considered as the input state greater than 6
PSI or less than 4 PSI. This interpretation is called Endpoint Active
State (EAS) on the Series 2
plus
because the endpoints of the range
are the areas which need to trigger action or generate alarms. The
opposite interpretation (though rarely used) is also possible and is
called Window Active State (WAS). Any input values between 4 PSI
and 6 PSI would trigger action or generate alarms.
If the ProControl has Alarms Set, when any input enters its active state, a local
beeper will sound on the ProControl. The word Alarm here applies only to the
sounding of a local beeper and is not associated with any process control. The
active state condition is indicated on the LCD display and can be acknowledged by
the operator. The beeper is silenced when it has been acknowledged or after 30
seconds have elapsed. The beeper only operates when the system is operating in
Manual mode.

EOS ProControl 2 plus Series Specifications

General

Brand	EOS
Model	ProControl 2 plus Series
Category	Controller
Language	English