Siemens QBM3700 Series User manual

Modbus Air Pressure Sensor with I/O extension
QBM3700..
User Guide
A6V11841988_en--_b Smart Infrastructure
2021-02-24

2 | 20 A6V11841988_en--_b
Contents
Legal note ............................................................................................................3
Safety notes in the data sheet................................................................................3
1Installation .................................................................................................4
1.1 Mounting .....................................................................................................4
1.2 Quick release fasteners and detached cover................................................5
1.3 Connecting tubes.........................................................................................6
1.4 Wiring..........................................................................................................6
1.4.1 Electrical grounding ......................................................................6
1.4.2 Power supply ................................................................................7
1.4.3 Connection terminals ....................................................................7
1.4.4 Signal wiring .................................................................................8
2Commissioning........................................................................................10
2.1 Address.....................................................................................................10
2.1.1 DIP switches (Climatix and other controllers)...............................10
2.1.2 On-event addressing (Climatix controllers)..................................10
2.1.3 Baud rate....................................................................................11
2.2 Fault detection, correction or reset.............................................................11
3Engineering..............................................................................................13
3.1 Implementing volume flow measurement ...................................................13
3.2 Modbus registers.......................................................................................13
4Maintenance.............................................................................................18
4.1 Fused mode analog outputs.......................................................................18
4.2 Zero reset..................................................................................................18
5Supplemental information.......................................................................19

Legal note
Safety notes in the data sheet
A6V11841988_en--_b 3 | 20
Legal note
This guide includes notes that must be followed for your own personal safety as
well as to prevent damage to property.
Notes dealing only with damage to property do not have the warning triangle and
use the signal word NOTICE and an exclamation point.
The notes are depicted as follows:
NOTICE
Type and source of hazard
Consequences in the event the hazard occurs
●Measures/prohibitions to prevent the hazard
Only qualified personnel may commission the device/system. In this regard,
qualified personnel have the training and experience necessary to recognize and
avoid risks when working with this device/system.
The device/system described here may only be used on building technical plants
and for the described applications only.
The trouble-free and safe operation of the device/system described here requires
proper transportation, correct warehousing, mounting, installation, commissioning,
operation, and maintenance.
You must comply with permissible ambient conditions. You must comply with the
information provided in the Section "Technical data" and any notes in the
associated documentation.
Fuses, switches, wiring and grounding must comply with local safety regulations for
electrical installations. Comply with all local and currently applicable laws and
regulations.
The content of this document was reviewed to ensure it matches the hardware and
firmware described herein. Deviations cannot be precluded, however, so that we
cannot guarantee that the document matches in full the actual device/system. The
information provided in this document is reviewed and updated on a regular basis.
Safety notes in the data sheet
NOTICE
Comply with all safety notes in data sheet "A6V11684000" in the sections
"Technical data" and "Notes".
Legal note concept
Qualified personnel
Intended use
Exemption from liability

Installation
Mounting
1
4 | 20 A6V11841988_en--_b
1 Installation
1.1 Mounting
NOTICE
Hint
Mount the sensor in a location that is easy to open the cover and access the
terminals, DIP switches and view the LEDs.
Proceed as follows to mount the sensor to a surface:
●Screw the sensor at the 2 brackets (on the device sides) to the mounting
surface.
●Keep the following guidelines
Fig. 1: All dimensions in mm
134
5.5
min. 75

Installation
Quick release fasteners and detached cover 1
A6V11841988_en--_b 5 | 20
1.2 Quick release fasteners and detached cover
●Open the housing with the quick release fasteners
●The cover is easy to remove
1
1
2
90°
2
2
1

Installation
Connecting tubes
1
6 | 20 A6V11841988_en--_b
1.3 Connecting tubes
Connect the tubes Avoid loops
1.4 Wiring
1.4.1 Electrical grounding
Note the following grounding situation of the QBM3700...
Transformer
Power-
supply
24V 0V
REF B- A+
Earth
Sensor module
Not isolated RS485
M
Starting point

Installation
Wiring 1
A6V11841988_en--_b 7 | 20
●QBM3700.. uses a non-isolated RS485-Interface.
●The reference of RS485 transceiver is connected to GND.
●All GND pins are on the same potential.
●If the Climatix controller and QBM3700.. are connected to the same power
source, take care to avoid incorrect wiring between 24 V input and GND.
The document "Modbus communication" (J3960) provides profound information
on Modbus grounding.
1.4.2 Power supply
Terminal 24V
≂
→, ,24V
≂
←
Diagram
Note Ground is optional.
1.4.3 Connection terminals
Power supply AC / DC 24 V
GND
Power supply for external devices AC/DC 24 V
Modbus® communication +
Common
Modbus® communication -
Analog output 1
GND
Analog output 2
Analog input 1
GND
Analog input 2
24
V
2
4
V
Consequence

Installation
Wiring
1
8 | 20 A6V11841988_en--_b
1.4.4 Signal wiring
The following graphics illustrate all signal types of a QBM3700...
1.4.4.1 Analog inputs
Analog inputs for passive sensors
Application Connecting passive temperature sensors.
Signal types: Pt1000, LG-Ni1000, NTC10k, and Ni1000
Terminal AI1, AI2
Diagram
Analog inputs for voltage signal
Application Connecting devices that supply a 0…10 V signal
Terminal AI1, AI2
Diagram
AI1 AI2
AI1 AI2
==

Installation
Wiring 1
A6V11841988_en--_b 9 | 20
1.4.4.2 Analog outputs
Analog outputs with voltage signal
Application Connecting devices that are controlled with a 0...10 V signal
Terminal AO1, AO2
Diagram
M
+
-
M
A
O
1
A
O
2
+
-

Commissioning
Address
2
10 | 20 A6V11841988_en--_b
2 Commissioning
2.1 Address
2.1.1 DIP switches (Climatix and other controllers)
Use DIP switches to adjust the Modbus address and for termination.
●The DIP-switches have priority over register 4x0764 (Modbus address).
●The Modbus address (register 4x0764) is valid as soon as all DIP switches are
on '0'.
●Changes to DIP switches are effective after 5 seconds.
Modbus addressing
The DIP switches allow addresses between 1…247 (Modbus specification).
The following example shows Modbus address '3':
Modbus termination
●The termination is done with 120 Ω+ 1nF.
●The termination must be done manually, even if the addressing is done with
"On-event addressing (Climatix controllers) [➙10]".
2.1.2 On-event addressing (Climatix controllers)
On-event addressing works together with Climatix controllers.
On-event addressing performs several functions that otherwise would have to be
done 'manually':
Workflow
The QBM3700.. sensor is wired and connected to the controller via Modbus.
The DIPs 1…8 (addressing DIPs) are set to '0'.
The on-event addressing functionality is configured in the application.
The necessary functional block is therefore available in the CAS library. The
CAS library online help contains further engineering documentation.
1 2 3 4 5 6 7 8 9
1
2
1: On
0: Off
128 64 32 16 8 4 2 1
1 2 3 4 5 6 7 8 9
1
2
1: On
0: Off
128 64 32 16 8 4 2 1
1 2 3 4 5 6 7 8 92
1: On
0: Off