Modbus air pressure sensor with I/O extension QBM97.. QBM97.. air pressure sensor with I/O extension is designed for Modbus RTU communication networks. The QBM97.. offers easy installation and reduced plant wiring efforts with HVAC industry wide proven sensor technology. ● ● ● ● ● ● ● ● ● A6V11478118_en_c 2021-01-20 Modbus RTU communication interface Two analog inputs for 0...10 V or passive temperature elements Two analog outputs for 0...
Type overview / order data QBM97.. Modbus air pressure sensor with I/O extension The QBM97.. comes with one or two sensor elements, different pressure ranges and with or without M12 connector for power and communication. QBM97.. without M12 connector Type/ASN QBM97..
Accessory Connection kits Type/ASN Stock number/SSN Designation MOQ AQB9120/101A S55843-Z120-A101 Connection kit for ventilation duct, 1 two metal nipples 90° angled, including one tube 2 m long AQB9220/101A S55843-Z220-A101 Connection kit for ventilation duct, 1 two plastic nipples, straight, including one tube 2 m long Field of application Focus segment ● Air handling units (AHU), with communication between controller and field devices and connected to cloud enabling plant digitalization.
Features description and benefits Sensor technology The built-in sensors of the QBM97.. are based on the unique and in HVAC and automotive industry well-proven ceramic strain-gauge beam technology. ● The accurate sensors with long-term stability for all measured variables are completely maintenance free, providing cost savings over the whole lifetime of the plant. ● The sensor elements are also suited for demanding applications in the food or pharmaceutical industry.
Operating elements PCB overview LED1 A ON 1 2 3 4 5 6 7 8 9 B Element Description A Status LED B DIP switches C Push button C Status LED indicator Color Flash response Function Red Blinking, 1 second on, 5 seconds off ● Red Blinking, 0.1 seconds on, 1 second ● off Invalid configuration Orange Continuous ● Waiting for on-event addressing Orange Blinking, 1 second on, 5 seconds off ● Bus communication failure Orange Blinking, 0.
Interfaces AI2 AI1 AO2 AO1 B- Ref A+ 24V 24V Terminals Terminal Description M12 pin 24V≂ → Power AC 24V / DC 24V 2 ⊥ GND 3 24V≂ ← Power supply external devices AC 24V / DC 24V A+, REF, B- Modbus, RS-485 NOTICE! Not galvanically separated AO1 ← Analog output 1 ⊥ GND AO2 ← Analog output 2 AI1 → Analog input 1 ⊥ GND AI2 → Analog input 2 4, 1, 5 M12 connector: Connector type code A, 5-pole A+ Ref 1 4 5 2 3 BGND Supply + Note: For description see table above 6 Siemen
Technical data Power data Power Operating voltage AC/DC 24 V ±15 % Frequency 50/60 Hz Protection class III (SELV / PELV), UL Class 2 NOTICE! Limited energy circuit 15 VA or less. Power consumption <2 VA Current draw AC max. 25 mA @ AC 24 V Current draw DC max. 25 mA @ DC 24 V 24V external power supply for active sensors max current: 80 mA Functional data Pressure measuring Ranges See "Type overview / order data [➙ 2]".
Limits Tolerable overload on one side ● ● on Px +: 10000 Pa on Px -: 400 Pa Rupture pressure ● ● at room temperature: 2x overload at 70 °C: 1.5x overload Media / Admissible temperature Air and neutral gases / 0…70 °C Maximal tube length 15 m Data for volume flow calculation Permitted k factor range 0...
Communication Modbus RTU communication Item Specification Address range 1...247 (255 = default) Baudrate 9˙600...57˙600 Format Modbus RTU Line termination selectable via DIP switch 9 Hardware RS485 Default configuration 9600E1 (9600 baud rate, 1 stop bit, even parity) Cable types Interface Specification Signal lines (Inputs/ outputs) Screw terminals for wire and stranded conductors: ● Wire: 0.5…2.5 mm2 NOTICE! Use copper conductors only. Cable bushings ● ● Modbus QBM97..
Inputs and outputs Analog inputs AI1, AI2 Type Range Accuracy Resolution TK/B25/85 Pt1000 -50...+150 °C ±0.5 K 0.1 K 3850 ppm/K LG-Ni1000 -40...+120 °C ±0.5 K 0.1 K 5000 ppm/K NTC10k -40...-25 °C ±1.0 K 0.2 K 3979 -25...+75 °C ±0.5 K 0.1 K 3979 +75...+100 °C ±1.0 K 0.3 K 3979 +100...+125 °C ±3.0 K 1.0 K 3979 +125...+150 °C ±6.0 K 2.5 K 3979 Ni1000 -50...+150 °C ±0.5 K 0.1 K 6180 ppm/K Input DC 0...
Conformity Ambient conditions and protection classification Classification as per EN 60730 Degree of pollution 3 Impulse voltage 330 V Degree of protection of housing to EN 60529 IP54 Climatic ambient conditions as per EN 60721-3 Transport / Storage ● ● Temperature: -30...+70 °C Air humidity: 5…90 % (non-condensing) Operation ● ● Temperature: -25...
Notes Safety: National regulations CAUTION National safety regulations Failure to comply with national safety regulations may result in personal injury and property damage. ● Observe national provisions and comply with the appropriate safety regulations. Mounting Mounting location QBM97.. air pressure sensor with I/O extension is suited for direct mounting on air ducts, walls, or in control panels. The following points must be observed. NOTICE Inaccurate measurements due to wrong mounting location.
Wiring NOTICE Polarity reversal protection The device is short circuit proof and protected against polarity reversal. Each connection is protected against crossover up to maximum supply voltage. Save mode and analog outputs The QBM97.. is delivered with a 'Save mode' function to prevent damage in the event of an open circuit to the Modbus connection. The analog outputs are switched to DC 0 V if communication is lost for > 60 seconds.
Dimensions QBM97.. (all dimensions in mm) 146 60 35.5 11.3 5. 5 81.9 45 134 9 10 33 42 Side view QBM97.. (here: without M12) 6 Front view QBM97.. (here: without M12) 40 6 3.4 60 78.5 100 1-4 16 151.4 70 28 6.5 4 16 56 175 Bottom view QBM97..
Modbus registers Supported function codes 03 (0x03) Read holding register 04 (0x04) Read input registers 06 (0x06) Write single register 16 (0x10) Write multiple registers Any changes of settings are completed with setting 4x0768 (Bus config command) to "1" (toggle bit).
Analog Output 1 Addr Description Unit Scaling R/W Range Data type 4x0027 Value mV 1 R/W 0 ≤ VAL ≤ 10500 uint16_t 4x0028 Dependence 1 R/W 0 = value @ 4x0027 = default if 4x0003=1 uint16_t 1 = with Analog input 1 2 = with Analog input 2 3 = with pressure sensor 1 = default if 4x0003=0 4 = with pressure sensor 2 4x0029 Scaling low - (0.0V) mV 1 R/W 0 ≤ VAL < Scaling high (0 = default) uint16_t 4x0030 Scaling high - (10.
4x0058 Dependence 1 R/W 0 = value @ 4x0057 = default if 4x0003=1 uint16_t 1 = with Analog input 1 2 = with Analog input 2 3 = with pressure sensor 1 4 = with pressure sensor 2 = default if 4x0003=0 4x0059 Scaling low - (0V) mV 1 R/W 0 ≤ VAL < Scaling high (0 = default) uint16_t 4x0060 Scaling high - (10V) mV 1 R/W Scaling low < VAL (10000 = default) uint16_t Unit Differential pressure 2 Addr Description Scaling R/W Range Data type 4x0065 Reliability 1 R uint16_t 4x0066 Value 1
Modbus Settings (according to Climatix) Addr Description 4x0764 Modbus address Unit Scaling R/W Range Data type 1 R/W 1 ≤ VAL ≤ 247 uint16_t 255 = default 4x0765 Baudrate 1 R/W 0 = auto (default) uint16_t 1 = 9600 2 = 19200 3 = 38400 4 = 57600 4x0766 Format 1 R/W 0 = 1-8-E-1 (default) uint16_t 1 = 1-8-O-1 2 = 1-8-N-1 3 = 1-8-N-2 4x0768 Bus config command 1 R/W 0 = ready (default) uint16_t 1 = load 2 = discard Addr Description 4x9014 Software version Issued by Siemens Switzerlan
