Technical Instructions
RWD62U Universal Controller
Document Number 155-737
January 14, 2005
P+I Limiter Function
NOTE:
In the following
illustrations, the
heating and cooling
outputs are D.A.
Outputs can be
reversed.
TH0794R1
X1
Y2
Y1
Temp.
Y
X2
Figure 9. P+I Limiter Function.
The limiter function with P+I control
enables absolute (or relative) maximum
or minimum limitation of the supply air
temperature (X2).
When the value drops below or exceeds
the limiter setpoint, the limiter function
controls and takes priority over the main
setpoint.
Remote Setpoint
NOTE:
You cannot select
the remote setpoint
auxiliary function in
Night mode.
X1
Y2
Y1
Temp.
Y
X2
TH0793R1
Figure 10. Remote Setpoint.
A remote setpoint transmitter (QAA25U),
connected to X2 and configured
accordingly, enables setpoint
adjustment.
Active measurement from 0 to 10 Vdc
corresponding adjustable range from
–100 to 8000 units
Passive measurement from 0 to 1000
Ω
corresponding adjustable range from
–100 to 8000 units
Cascade Control
TH0794R1
X1
Y2
Y1
Temp.
Y
X2
Figure 11. X2 Supply Air Temperature
Sensor.
You can select the P+I/P+I room/supply
air temperature cascade control. In this
case, the virtual P+I room temperature
controller determines the setpoint within
the limiter setpoints for the P+I supply air
temperature controller.
Maximum Priority
NOTE:
You cannot select
the maximum priority
auxiliary function in
Night mode.
TH0795R1
X2
Y2
Y1
Temp.
Y
X1
Figure 12. Maximum Priority,
Cooling.
If the value (0 to 10V) of the input X2 is
greater than the calculated output of the
cooling sequence, the output will use the
X2 input value as output value. This is
active even when the controller is
working with the heating sequence.
Setpoint Compensation
TH0796R1
X2
Y1
Temp.
Y
X1
Figure 13. Setpoint Compensation.
The temperature setpoint X1 is shifted
by the temperature as measured at
sensor X2.
Configuration of the RWD62U defines
the influence on setpoint X1.
The example shows the room air
temperature setpoint as shifted by the
outside temperature.
Page 6
Siemens Building Technologies, Inc.
