OPLC-2100 Operation Manual
CONFIDENTIAL
21 Harbor Park Dr. N, Port Washington Phone: 516.656.72211 Fax: 516.626.7201
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2. Operation Basics
The OPLC-2100 controller (“” version) is designed to provide automatically regulated heat distribution by cycling a
boiler on and off and modulating the flame. The controller continuously calculates the amount of heat requested by the
building taking into account the outdoor temperature, heating system temperature, boiler’s steam pressure and selected
settings. Then the controller assumes that this requested heat value is actually the average heat amount, which must be
delivered to the building. Knowing the CYCLE setting the controller calculates the ‘ON’ part of the cycle and controls the
flame modulation. To achieve an optimal performance of the heating system a discrete Proportional-Integral-Derivative
(PID) algorithm is implemented in the “” system. Based on generic control loop feedback mechanism the PID
controls flame modulation.
It makes sense to have some constant period of the boiler operation (CYCLE), which, in turn, is divided to ‘ON’ part of
the cycle, during which the boiler is on, and the rest of the cycle, when the boiler is off (‘OFF’ part). In such a scheme of
boiler operation the average amount of heat delivered to a building is proportional to the ratio of’ ON’ and CYCLE values.
In brief, the controller calculates the heat amount requested by the building (percents) and transforms this value to the
parameters of the boiler cycle (minutes). Main goal of the PID control is supporting stable value of the boiler’s pressure
which is define by pressure set point and three PID parameters. Controller attempts to correct the error between measured
pressure and desired pressure set point by calculating and then outputting corrective action (open or close ) to the boiler’s
Gas Valve actuator. Special sequence of the functionality for the “” is implemented to provide proper control of the
boiler during the ‘ON’ part of the Cycle (Fig.3). The flame modulation can starts after the certain period of time called
“Purge” when Gas Valve position achieves special set point (called ‘LFR’ – Low Frame Rate) and after ‘Purge Delay’ set
point. Switch from the ‘ON’ part of the cycle to the ‘OFF’ part of the cycle required “Post Purge” period which includes
time for moving Gas Valve from a point where it was during on the ‘ON’ part to the LFR set point and shat down the boiler.
After ‘Post Purge Delay’ the Valve returns to the zero position. The PID control is active on the Heat Up state and D
(N):Norm state of the Heating Cycle (Fig.3).
3. Controls
The four-button keypad and 16 characters by 2 lines LCD backlit display can be found on the front panel of the
OPLC-2100. These controls provide full local management of the system. Operator can read system status information (e.g.
temperatures, pressure, cycle parameters, and alerts), set the operational modes, and change settings. The control keypad
consists of four pushbuttons: Escape (Esc), Down (
), Up (
), Enter (Enter). The keys are also marked with letters A, B,
C, D to simplify the passwords memorizing. Holding down the (
) or (
) keys will speed up decrement or increment of
setting parameters.
Upper line of the display shows current mode of operation (AUTO, MANUAL, or SET), percentage of heat
requested, and the operational status. Lower line is dedicated to show system status information and setup dialog.
4. Menu
The process of interaction is menu driven. Menu chart is shown on Fig 2. The menu is organized in convenient and
logical way, and follows a simple set of rules.
The menu chart is organized as a set of menu boxes. To navigate between the boxes one should press
Enter key to move to the right on the chart and Esc key to move backward.
Each box contains one or more menu items. To switch between the items inside a box one should press Up
or Down keys.
Each item represents one menu entry: select a setting to change, enter a new setting value, change mode of
operation etc.
If the item contains "NEW" word then the new value has to be entered: Pressing Up and Down keys
change the value. Pressing the Enter key accepts the new value. Esc key rejects the new value, and leaves
the setting unchanged.
If a password is required then one should enter a certain key sequence. For convenience the passwords are
coded as a sequence of letters (e.g. DDBBCBA).
Starting point of the menu is the topmost item of the leftmost box, which is a current cycle parameters line
in the chart. If lost in the menu just press Esc repeatedly, until the display shows something like:
"Cyc:29/61 ON:12”. You are now in the upper left corner of the menu chart.
Summary of Contents for OPLC-2100
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