Siemens RWD Series Controller Full Parameter Guide for HVAC Systems

 📘 Complete Siemens RWD68, RWD32 & RWD82 Universal Controller Settings Guide | HVAC Automation Explained

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This comprehensive guide explains how to configure Siemens RWD68, RWD32, and RWD82 universal controllers for HVAC systems. Whether you're a technician, engineer, or HVAC specialist, you’ll learn the essential functions, parameter settings, and programming steps to ensure optimal performance in building automation.

🔧 Siemens RWD68 / RWD32 / RWD82 Universal Controllers

🔧 Overview

• Siemens RWD series controllers are advanced digital controllers for HVAC and building automation.
• Designed for temperature, pressure, and humidity control in heating, ventilation, air-conditioning, and refrigeration systems.
• RWD32 and RWD82 are ideal for comfort control plants and support various measurements: temperature, RH, enthalpy, airflow, and more.
• Each controller must be configured with a plant-specific application number.
• The Siemens RWD32, RWD68, RWD82 controllers are intended for either DIN rail mounting in a switchboard or screw mounting with protective enclosure.

🔌 Inputs & Outputs Overview

RWD32 Controller:

• Operating Voltage: AC 230 V
• Universal Inputs (UI/AI): 2
• Digital Inputs (DI): 1
• Digital Outputs (DO): 2

RWD82 Controller:

• Operating Voltage: AC 24 V
• Universal Inputs (UI/AI): 2
• Digital Inputs (DI): 1
• Digital Outputs (DO): 2

RWD68 Controller:

• Operating Voltage: AC 24 V
• Universal Inputs: 2
• Digital Input: 1
• Analog Output: 1
• Digital Output: 1

Siemens RWD Series Controllers

🧠 Controller Features

The RWD68, RWD32 and RWD82 is a stand-alone universal controller which performs both primary and auxiliary control functions. 

The respective mode is defined by entering the corresponding configuration and setting parameters via the push buttons on the controller or the software tool.

Universal input X1:

• The universal input X1 is used as the primary input for a Ni 1000 temperature sensor, 
• a Pt 1000 temperature sensor or a 0-10 Volt DC active input.

Universal input X2:

• The universal input X2 is used as the secondary input for a Ni 1000 temperature sensor, a Pt 1000 temperature sensor, 
• an active or passive remote setpoint transmitter or a 0-10 Volt DC active input.

Digital input D1:

• The digital input D1 is used to select the day or night changeover.
• Changeover occurs via potential-free contacts between D1 and M.

Digital outputs Q:

• Each output Q (Q1, Q2) can be configured for either reverse or direct acting.
• Q is a digital output that supports AC voltage ranging from 24 to 230 Volt.

🖥️ LCD Display & Operation

• The RWD32, RWD68 and RWD82 are operated by the buttons on the controller front.

• Additional tools are not necessary.

• A 9-pin port is provided for optional programming via the software tool.

📷 Front panel of Siemens RWD68 showing LCD display and buttons

The LCD shows the following information for normal operation:

• Current operating values (maximum 4 digits),

• Current setpoints (day/night),

• Application number,

• Control sequencing diagram,

• Auxiliary input value,

• Selected auxiliary function,

• The controller has three operating buttons for the following functions,

• The SELECT button is used to enter or save the value adjustment.

• The Up/Down or Increment/Decrement operating buttons are used for viewing and adjusting parameters.

💻 Software Tool

• A software tool for controller application selection and parameter adjustment is available.

• It is a user-friendly Windows 95 (or) above based software tool which provides you a printout of the controller settings.

📎 Related: Siemens PXM40 HMI Touch Panel Commissioning: A Step-by-Step Guide with Images

⚙️ Programming Modes (Parameter Screens)

• PS-1 Parameter Setting Mode: Application No. Setup,

• PS-2 Parameter Setting Mode: Defining Unit, X1 and X2,

• PS-3 Parameter Setting Mode: Auxiliary Control,

• PS-4 Parameter Setting Mode: Main Control Loop Setting,

• PS Next To enter the next Parameter Setting,

• PS Exit To exit the whole Parameter Setting Mode,

🔵 PS1 - Application No. Selection:

Parameter Setting Mode PS1

Name	Description	Display, Setting Range
LIM ABS	Absolute Limiter	x
WIN/SUM  diG	Winter/Summer changeover by digital input	x
Act	Active sensor input	x
LIM rEL	Relative Limiter	x
WIN/SUM AnLG	Winter/Summer changeover by analogue input	x

🔵 PS2 - Unit, X1 & X2 sensor type and sensing range definition:

Parameter Setting Mode PS2

Name	Description	Display, Setting Range
UNT	Unit define	°C, °F, % or ----(no unit display)
X1LS	X1 is Landis & Staefa Ni 1000Ω temperature sensor	Ni 1000Ω: -50 to 150°C (unchangeable)
X2LS	X2 is Landis & Staefa Ni 1000Ω temperature sensor	Ni 1000Ω: -50 to 150°C (unchangeable)
X1Pt	X1 is Platinum Pt 1000Ω temperature sensor	Pt 1000Ω: -20 to 180°C (unchangeable)
X2Pt	X2 is Platinum Pt 1000Ω temperature sensor	Pt 1000Ω: -20 to 180°C (unchangeable)
X1 0-10	X1 is 0-10 Vdc input sensor	0-10 Vdc: -100 to 8000
X2 0-10	X2 is 0-10 Vdc input sensor	0-10 Vdc: -100 to 8000
ΔX1	Calibration offset for X1 (Ni & Pt sensor only)	-5.5 K or -9°F to 9°F
ΔX2	Calibration offset for X2 (Ni & Pt sensor only)	-5.5 K or -9°F to 9°F
X2 L	Start point of the X2 (for 0-10 Vdc only)	-100 to 8000
X1 H	Stop point of the X1 (for 0-10 Vdc only)	-100 to 8000
X2 H	Stop point of the X2 (for 0-10 Vdc only)	-100 to 8000
X2VR	Variable Resistor	0 to 1000 Ω

Note:

Landis & Staefa is Legacy Swiss brand for HVAC and building control systems, now fully integrated into Siemens Building Technologies.

🔵 PS3 - Auxiliary Control Loop Setup:

Parameter Setting Mode PS3

Name	Description	Display, Setting Range
XP-h	Proportion band for heating	• Ni: 0.5.180 K • Pt: 0.5.180 K • Active input: 0.05.7300
XP-c	Proportion band for cooling	• Ni: 0.5.180 K • Pt: 0.5.180 K • Active input: 0.05.7300
XP-r	Proportion band for reverse acting	Active input: 0.05 to 7300
XP-d	Proportion band for direct acting	Active input: 0.05 to 7300
TN-h	Integral action time for heating	0.4096 sec
TN-c	Integral action time for cooling	0.4096 sec
TN-r	Integral action time for reverse acting	0.4096 sec
TN-d	Integral action time for direct acting	0.4096 sec
T	Time elapsed to allow next winter/summer changeover (Q1 only)	0.4096 sec
	Compensation shift (Start point, End point & Shift differential)	x
MAX	Maximum Limiter	-80 to 8000
MIN	Minimum Limiter	-100 to 7980
WIN	Winter changeover point	-100 to 8000
SUM	Summer changeover point	-100 to 8000

🔵 PS4 - Main Control Loop Setup:

Parameter Setting Mode PS4

Name	Description	Display, Setting Range
T1	Minimum switch off time for Q1	0 to 255 sec
T2	Minimum switch off time for Q2	0 to 255 sec
TCYC	Cycle time of the actuator	1 to 255 sec
ON	Dependent loop. On point of Q1 as a % of total (Q1+Q2) SD	0 to 100 %
TN3P	I time for 3-point actuator	0 to 4096 sec
XP3P	P band 3-point actuator	0.05 to 7300 (Depends on the X1 setting range)
SD	Switching Differential	0.05 to 7300

⚠️ Notes:

Time-out 🕓

• For set-point adjustment in Normal mode, the controller will exit the setting after 20 seconds automatically.  

• However, for set-point adjustment in Service (PS) mode, there is no time limit.  

• The controller remains on the PS mode until the user completes the whole process.

🎯Application Number Summary:

✔ H = Heating, 

✔ C = Cooling, 

✔ R = Reverse Acting, 

✔ D = Direct Acting,

✔ The 1st digit denotes = Main Control Loop, 

✔ The 2nd digit denotes = Auxiliary Control Loop,

✔ Depend = The second output is dependent on the status of the first output.

✔ Independ = The second output operates independently of the first.

Application No. Summary

Application No	Main Control Loop
#10, #11, #12, #13, #14, ---,  ---,  ---,  ---, #19	H+H or R+R depend
#20, #21, #22, #23, #24, ---,  #26, #27, ---, #29	H+H or R+R independ
#30, #31, #32, #33, #34, #35, #36, #37, ---, #39	H or R 3-position
#40, #41, #42, #43, #44, ---,  #46, #47, ---, #49	H+C or R+D
#50, #51, #52, #53, #54, ---,  ---,  ---,   ---, #59	C+C or D+D depend
#60, #61, #62, #63, #64, ---,  ---,  ---,  ---, #69	C+C or D+D independ
#70, #71, #72, #73, #74, #75, ---,  ---, #78, #79	C or D 3-position

#x0 No auxiliary🧩

#x1 Remote Setpoint🧩
#x2 Absolute limiter🧩

#x3 Relative limiter🧩

#x4 Compensation shift

#x5 Cascade🧩

#x6 Winter/Summer digital🧩

#x7 Winter/Summer analog🧩

#x8 Maximum priority🧩

#x9 Main loop (active input)🧩

💡Example: #22 Application

✔️ Main Control Loop =  H+H or R+R independ,

✔️ Auxiliary Control Loop = Absolute limiter,

📈 Display Symbols Explained

Name	Description	Display, Setting Range
#10	Application Number	10 to 59 (Not consecutive numbers)
☼	Day time operation	x
☽	Night time operation	x
X1	Universal (Main) Input X1	Ni 1000Ω: -50 to 150°C (unchangeable), Pt 1000Ω: -20 to 180°C (unchangeable), 0-10 Vdc: -100 to 8000,
X2	Universal (Auxiliary) Input X2	Ni 1000Ω:  -50 to 150°C (unchangeable), Pt 1000Ω:  -20 to 180°C (unchangeable), 0-10 Vdc: -100 to 8000, Variable resistor: the resistance range should within 0 to 1000 Ω,
----	No unit (e.g. pressure, air quality and air volume flow),	x
Sec	Second	x
Y1	Analogue output 1	x
Y2	Analogue output 2	x
°C	Celsius scale	x
°F	Fahrenheit scale	x
K	Kelvin	x
%	Percentage scale (e.g. RH)	x
TOOL	PC communication port  being used	x
OUT RANGE	The setting is out of range	x
Err	Sensors error	x
#10★	★Using not the defaulted sensor	x
WIN/SUM	Winter/Summer mode being chosen or activated	x
LIM	Limiter mode being chosen or activated	x
REM	Remote setpoint mode being chosen or activated	x
CAS	Cascade mode being chosen or activated	x
MaxPrior	Maximum priority mode being chosen or activated	x
SP-h	Setpoint on the heating side for temperature control	x
SP-c	Setpoint on the cooling side for temperature control	x
SP-r	Setpoint on the reverse acting side for active input (0 10 Vdc)	x
SP-d	Setpoint on the direct acting side for active input (0 10 Vdc)	x
XDZ	• For R or D independent loops. Day setpoint offset from the first output to the second output when in REM mode. • For R+D application. Dead zone between R and D day setpoints when in REM mode	Ni: 0.5 180 K Pt: 0.5 180 K Active input: 0.05 to 7300

🚨Sample Application Settings

This sample application setting is only suitable for monitoring and control the humidity and temperature with day mode operation and turning on/off the two (2) Relay outputs such as a water pump, fan, air cooler, and more.

Note:

This sample setup is only suitable with the Siemens RWD82 controller.

⚙️PS1

Application no: #22

⚙️PS2

UNT: ---

X1: 0-10

X1L: 0

X1H: 100

X2: 0-10

X1L: 0

X1H: 50

⚙️PS3

MAX: 50.0

MIN: 0.0

⚙️PS4

Q1 SD: 2.0

Q2 SD: 2.0

Q1 SP--r ☼: 60

Q2 SP--r ☼: 55

Q1 SP--r ☽: 60

Q2 SP--r ☽: 55

🏁Conclusion:

• The Siemens RWD32, RWD68 and RWD82 universal controllers are robust, programmable solutions for a wide range of HVAC control applications. 

• Their ease of configuration, reliable performance, and adaptability make them essential tools for smart building automation.

• Understanding how to properly configure control parameters ensures optimal functionality, reduced energy consumption, and long-term reliability.

• Keep following for more in-depth guides on HVAC controllers and automation systems!

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