SRD2 - NEW - Wall Mounted


Wall-mounted programmable indoor controller and transmitter (X2 OS) with temperature and humidity sensor with optional CO2, VOC air quality, dust particle sensor, color display, IR sensor and communication

VC logo temperature.jpg

VC logo humidity.jpg

VC logo co2.jpg

VC logo voc.jpg

VC logo dust.jpg

VC logo infrared.jpg

VC logo analog output.jpg

VC logo digital output.jpg

VC logo bacnet.jpg

VC logo modbus.jpg

VC logo wifi.jpg

VC logo x2 os.jpg



The SRD2 is a programmable controller and transmitter with communication capabilities. Each control loop may use 2 PI sequences and 2 binary stages. The SRD2 comes with a built-in isolated RS485 communication interface that allows peer-to-peer communication with an operation terminal such as OPT1-(2TH)-VC. An optional built-in color display and touch buttons provides a perfect and flexible way to interact with the user.

Communication supports BACnet or Modbus. There is also a Wi-Fi communication option available which supports Modbus TCP and BACnet/IP. An embedded webserver provides a web interface to access the controller in order to change the connection settings and to operate the controller.

Complete parameter sets may be copied by use of an accessory called AEC-PM2 or exchanged with a PC and the EasySet program using an RS485-USB converter or via Wi-Fi.

The SRD2 uses the Vector Controls universal and flexible X2 operating system and is preconfigured as described in the manual.



  • Ventilation control 
  • Temperature control 
  • Air humidifier and dehumidifier
  • CO2 air quality control 
  • VOC air quality control 
  • Dust particle air quality control
  • Motion detection action


Type Overview (see ordering for details)

SRD2 with
display and IR sensor
SRD2 without
display and IR sensor

SRD2-OPIR 300x350.jpg


SRD2-x 300x350.jpg



Here are some samples of possible standard displays (not complete):
  SRD2 Samples of standard display.jpg


Dimensions, mm (inch)



  • Two universally configurable control loops: 
    • Functions for dehumidifying, set point shift and cascade control 
    • Multiple auxiliary functions: heat-cool auto changeover, automatic enable, set point compensation 
    • Free heating and cooling with economizer function based on enthalpy or temperature 
    • Differential, averaging, min and max functions, enthalpy and dew point calculations 
    • Transmitter function for sensors and set points 
  • Measures:
    • Temperature
    • Humidity
    • CO2
    • VOC air quality
    • Dust particles (PM1.0, PM2.5, PM10) 
  • A passive infrared sensor (-IR type) which can be used for motion detection (occupied / unoccupied)
  • Color display with backlight and touch button operation (-OP type)
  • Built-in humidity and temperature sensor (-TH type), CO2 sensor (-C type), VOC sensor (-Q type), 
    dust particle sensor (-D type) 
  • 3 analogue voltage outputs (VDC) and one relay with a normally open and a normally closed contact (SPDT) 
  • 8 freely assigned alarm conditions, selectable state of outputs and sounds on alarm condition 
  • Serial Modbus RTU/ASCII or BACnet MS/TP via isolated RS485 
  • Modbus TCP or BACnet/IP via Wi-Fi 
  • Webserver for SRD2 operation from computer / mobile device or via “EasyX2” desktop/mobile app 
  • Password protected programmable user and control parameters 
  • EasySet access over TCP/IP for configuration (Wi-Fi interface required) 


 Product Name

 Product No.


 SRD2-TH-220.103  40-300255
    2 control loops
    3 universal inputs
    2 digital outputs
    2 analog outputs
 TH = Temperature and humidity sensor
 C = CO2 sensor
 Q = VOC air quality sensor
 D = Dust particle sensor
 OP = Color display and touch buttons
 IR = IR (PIR) sensor for motion detection
 MOD = Communication with Modbus RTU or ASCII
 BAC = Communication with BACnet MS/TP
 WIM = Communication with Modbus TCP over Wi-Fi
 WIB = Communication with BACnet/IP over Wi-Fi
 SRD2-TH-220.103-MOD  40-300216
 SRD2-TH-220.103-BAC  40-300217
 SRD2-TH-220.103-WIM  40-300218
 SRD2-TH-220.103-WIB  40-300219
 SRD2-TH-220.103-OPIR  40-300256
 SRD2-TH-220.103-OPIR-MOD  40-300253
 SRD2-TH-220.103-OPIR-BAC  40-300254
 SRD2-TH-220.103-OPIR-WIM  40-300220
 SRD2-TH-220.103-OPIR-WIB  40-300221
 SRD2-THC-220.103  40-300252
 SRD2-THC-220.103-MOD  40-300222
 SRD2-THC-220.103-BAC  40-300223
 SRD2-THC-220.103-WIM  40-300224
 SRD2-THC-220.103-WIB  40-300225
 SRD2-THC-220.103-OPIR  40-300226
 SRD2-THC-220.103-OPIR-MOD  40-300227
 SRD2-THC-220.103-OPIR-BAC  40-300228
 SRD2-THC-220.103-OPIR-WIM  40-300229
 SRD2-THC-220.103-OPIR-WIB  40-300230
 SRD2-THQ-220.103-OPIR  40-300231
 SRD2-THQ-220.103-OPIR-MOD  40-300232
 SRD2-THQ-220.103-OPIR-BAC  40-300233
 SRD2-THCQ-220.103-MOD  40-300250
 SRD2-THCQD-220.103-OPIR-MOD  40-300234
 SRD2-THCQD-220.103-OPIR-BAC  40-300235
 SRD2-THCQD-220.103-OPIR-WIM  40-300215
 SRD2-THCQD-220.103-OPIR-WIB  40-300236
 SRD2-THCQD-220.103-MOD  40-300237
 SRD2-THCQD-220.103-BAC  40-300238
 SRD2-THCQD-220.103-WIM  40-300239
 SRD2-THCQD-220.103-WIB  40-300240
 SRD2-D-220.103  40-300251
   Pre-Configured Versions
 SRD2-TH-220.103-W8  40-300255-8
 W8 = Dew point sensor, ISO unit °C
 W28 = Dew point sensor, Imperial unit °F
 W9 = Enthalpy sensor, ISO unit kJ/kg
 W29 = Enthalpy sensor, Imperial unit BTU/lb
 SRD2-TH-220.103-W28  40-300255-28
 SRD2-TH-220.103-W9  40-300255-9
 SRD2-TH-220.103-W29  40-300255-29
 SRD2-TH-220.103-OPIR-W8  40-300256-8
 SRD2-TH-220.103-OPIR-W28  40-300256-28
 SRD2-TH-220.103-OPIR-W9  40-300256-9
 SRD2-TH-220.103-OPIR-W29  40-300256-29



Temperature Sensors
Sensing elements or accessories for temperature sensors
X2-Operation Terminals
Remote and built-in operation terminals
AEC-PM2 - Memory
External memory for parameter sets for X2-series
AEC-USB - USB to RS-485 Converter Cable Kit
For programming X2-devices with EasySet tool


Operation Manual

Install Sheet

Application Notes