Room Humidity and Air Quality Sensors: – QFA2050/MO, QFA2050D/MO – QPA2052/MO Modbus RTU (RS-485) Basic Documentation A6V12045847_en--_a 2020-07-23 Smart Infrastructure
Table of Contents 2 | 14 1 1.1 1.2 About this document ............................................................................. 3 Revision history ...........................................................................................3 Before you start ...........................................................................................3 2 2.1 2.2 Product overview ................................................................................. 5 Type summary.............................
About this document 1 Revision history 1 About this document 1.1 Revision history Edition Date Changes Section a 2020-07 First version. All 1.2 Before you start Copyright This document may be duplicated and distributed only with the expressed permission of Siemens Switzerland Ltd. Quality assurance These documents were prepared with great care. ● The content of all documents is checked at regular intervals. ● All necessary corrections are included in subsequent versions.
1 About this document Before you start ● ● 4 | 14 From your Siemens branch office www.siemens.com/sbt or at your system suppliers. From the support team at headquarters fieldsupport-zug.ch.sbt@siemens.com if no local POC is available. Siemens assumes no liability to the extent allowed under the law for any losses resulting from a failure to comply with the aforementioned points or for the improper compliance of the same.
Product overview Type summary 2 2 Product overview The sensors are used in ventilation and air conditioning plants. 2.1 Type summary Product number SSN No. Measurement parameter CO2 Temperature Relative humidity Output signal QFA2050/MO S55720-S508 - -40...70 °C 0…100 % r.h. Modbus RTU QFA2050D/MO S55720-S509 - -40…70 °C 0…100 % r.h. Modbus RTU QPA2052/MO S55720-S510 0…2000 ppm -40…70 °C 0…100 % r.h. Modbus RTU 2.
3 Wiring 3 Wiring 6 | 14 G Operating voltage AC 24 V ±20 % or DC 13.5...
Configuration DIP switch to configure method selection 4 4 Configuration 4.1 DIP switch to configure method selection The sensor is a Modbus RTU (RS-485) slave device and can be configured with a Modbus master when DIP2-Position 7 is OFF (default setting). The sensor has two sets of DIP switches: DIP1 and DIP2 and can be manually configured with DIP switches when DIP2-Position 7 is ON. For details, see DIP switch configuration [➙ 9]. 4.
4 Configuration Modbus registers Name Range/numeration Default Identity Slave - Cable length < 600 m - NOTES: ● Register 764 (Modbus address) cannot be configured as 246 via a master. Address 246 is reserved for on-event addressing. 4.3 Modbus registers Holding Register (16-bit) No. Description Range Unit Scaling Default R/W 1 Temperature value -327…327 °C °C 0.01 - R -556.6…620.
Configuration DIP switch configuration ● ● ● ● 4 The register number starts at 1. The sensor rejects a command with an error notice in the event of a multiplewriting command from the master with invalid values. The register values remain unchanged. Software version format: Major version is 1 byte, minor version is 1 byte and build version is 2 bytes, such as [2.01.33] = 0x02010021. Supports only the holding register. 4.
4 Configuration DIP switch configuration 27 26 25 24 23 22 21 20 Address 1 2 3 4 5 6 7 8 OFF OFF OFF OFF OFF OFF OFF OFF 0 (default) OFF OFF OFF OFF OFF OFF OFF ON 1 OFF OFF OFF OFF OFF OFF ON OFF 2 OFF OFF OFF OFF OFF OFF ON ON 3 OFF OFF OFF OFF OFF ON OFF OFF 4 … … … … … … … … … ON ON ON ON ON ON ON ON 255 NOTES: ● Modbus address configuration: Valid address range 1…247, others = 0 ● Newly set values of register 764…766 are
Configuration Bus termination 4 4.
5 Maintenance Disposal 5 Maintenance 5.1 Disposal The device is considered an electronic device for disposal in accordance with the European Guidelines and may not be disposed of as domestic garbage. ● Dispose of the device through channels provided for this purpose. ● Comply with all local and currently applicable laws and regulations.
Appendices Cyber security disclaimer 6 6 Appendices 6.1 Cyber security disclaimer Siemens provides a portfolio of products, solutions, systems and services that includes security functions that support the secure operation of plants, systems, machines and networks. In the field of Building Technologies, this includes building automation and control, fire safety, security management as well as physical security systems.
Issued by Siemens Switzerland Ltd Smart Infrastructure Global Headquarters Theilerstrasse 1a CH-6300 Zug +41 58 724 2424 www.siemens.com/buildingtechnologies © Siemens Switzerland Ltd, 2020 Technical specifications and availability subject to change without notice.
