PRT CTRL Integrated Controller Reference Manual

7 Fresh Air Cooling Set Point
If the fresh air cooling set point is not 0 the system will check the
fresh air temperature when a cooling demand exists and modulate
the dampers to allow free cooling. The system will remain in the
free cooling mode for the time set by the free cooling time.
8 Stage 1 Demand Value
The stage one demand value is the amount of plant error that is
required to activate the first stage of cooling or heating. Plant error
is calculated using a custom PI loop. The error is accumulated
using the settings for the Integral Value and Hysterisis Settings.
The error value is the difference between the set point and the
current space temperature with the addition of the accumulated
error.
9 Stage 2 Demand Value
The stage two demand value is the amount of plant error that is
required to activate the second stage of cooling or heating.
10 Stage 3 Demand Value
The stage three demand value is the amount of plant error that is
required to activate the third stage of cooling or heating.
11 Stage 4 Demand Value
The stage four demand value is the amount of plant error that is
required to activate the fourth stage of cooling or heating.
12 Current RTHP Mode
The current mode that the RTHP is operating in. The RTHP modes
are listed in the section below.
13 Current Plant Error
The current plant error is the error in the temperature value
difference between the set point and the current temperature. This
value is for display only and used to calculate the drive required
for the RTHP to obtain the desired set point.
14 Integral Error
The integral error is the amount of raw calculated error using the
integral portion of the PI loop used for the control of the RTHP unit
and is calculated ONLY in a cooling or heating requirement mode.
15 Integral Term
The integral term is the result of a calculation using the integral
gain and the integral error to obtain a value that can be used to
add with the Plant Error to ensure that the heating and cooling set
points are meet with the maximum amount of efficiency.
16 Output Error
The output error is the absolute output error at the current point
and can be used as a guide when tuning the RTHP. The output
error represents the Integral Term added with the raw Plant Error
values. The output error is used to calculate the staging of the
heating and cooling within the RTHP unit.
17 Integral Gain
Protégé Integrated System Controller Reference Manual
290