EOS ProControl 2 plus Series User Manual

ProControl User’s Manual v2.2X
6 \8100\0074_1017
Manual
Operation
You can override the Series 2
plus
programmed control functions by operating in
Manual Mode. In manual mode, your process will respond only to operator input
from the keypad of the ProControl, or to commands issued from the ProView
software. PLEASE NOTE THAT PROCESS TASKS AND THEIR ERROR-CHECKING
MECHANISMS DO NOT RUN DURING MANUAL MODE! Manual mode is useful when
you wish to troubleshoot your system, but none of the system safeguards built into
auto mode are available. You can place your operation into auto mode any time by
issuing the command from the keypad.
Analog Output
Processes
In some cases, you may want to use an analog output to control equipment that
maintains an analog input at a certain constant level. For example, you may wish to
automatically maintain a pH of 8.5 in a reaction tank by varying the dosing rate of a
chemical feed pump. The pH you wish to maintain (8.5) is called the SetPoint of the
analog output process. An analog input to the ProControl (in this case, a pH
transmitter) is said to provide feedback to the unit, and combined with an analog
output, constitute feedback control.
PID Loops
A reliable type of feedback control can be obtained through a PID Loop. PID
stands for Proportional-Integral-Derivative, and is a commonly-used process
control technique. We! ll skip the details of the mathematics involved, but suffice it
to say that a PID loop is the favored control technique for most analog output
processes. With only a Proportional term applied in the equation, the analog output
is controlled based on an error signal generated from the difference between the
SetPoint and the actual analog input. The PID loop can also improve its
performance as it continues to run if an Integral term is used, and can respond to
quick changes in the controlling analog input if a Derivative term is used. EOS
Research or your control system integrator will configure your PID loops for you
and can provide further information if necessary.
Proportional
Outputs
In some cases, it may be desirable to base an analog output signal on an analog input
value. In this situation, no specific SetPoint is used because there is a direct
relationship between the output and input values. For example, if you wanted to
base the output of a metering pump on some flow rate, you might use a proportional
output to relate the amount of chemical metered to the flow rate.

EOS ProControl 2 plus Series Specifications

General

Brand	EOS
Model	ProControl 2 plus Series
Category	Controller
Language	English