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.
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| Siemens RWD68 / RWD32 / RWD82 Universal Controllers |
- Variable controllers play a critical role in modern HVAC systems by regulating temperature, humidity, airflow, and pressure to maintain comfortable indoor conditions and efficient energy usage.
- The Siemens RWD series controllers, including RWD32, RWD68, and RWD82, are universal HVAC controllers designed for standalone operation in building automation systems.
- These controllers support various sensor inputs and provide flexible configuration options for heating, cooling, and refrigeration control.
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
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| 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.
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| 📷 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.
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:
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| 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:
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| 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:
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| 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
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| 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.
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| 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 auxiliaryx1 Remote Setpoint
x2 Absolute limiterx3 Relative limiterx4 Compensation shiftx5 Cascadex6 Winter/Summer digitalx7 Winter/Summer analogx8 Maximum priorityx9 Main loop (active input)
x2 Absolute limiter
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 |
|
| X2 | Universal (Auxiliary) Input X2 |
|
| ---- | 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 |
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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
Commissioning Procedure
- Power ON the controller
- Select the application number
- Configure input sensors
- Set control parameters
- Configure relay outputs
- Test system operation
Typical Applications of RWD Controllers
RWD controllers are used in:
- Air handling units (AHU)
- Fan coil units
- Heat pump systems
- Refrigeration control
- Boiler and chiller control
They can control single or multi-stage heating and cooling equipment, compressors, and ventilation systems.
Common RWD Controller Problems
- Sensor error (Incorrect sensor type)
- No output response (Wrong application number)
- Incorrect temperature (Sensor calibration error)
- Relay not switching (Wiring fault)
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!
FAQ (Frequently Asked Questions)
1. What is the Siemens RWD controller used for?
It is a standalone HVAC controller used for temperature, humidity, and pressure control in building automation systems.
2. What sensors are supported by RWD controllers?
Ni1000, Pt1000 temperature sensors and 0–10 V analog signals.
3. What is the application number in RWD controllers?
The application number defines the control strategy used by the controller.
About the Author – Insight Control System
Insight Control System provides technical education and practical guidance in the fields of Building Automation Systems (BAS), HVAC controls, PLC programming, sensors, and industrial automation. The content published on this platform is based on field experience, technical documentation analysis, and real-world system applications.
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