RDM adds Bluetooth wireless mesh control
11th November 2020
UK: Resource Data Management (RDM) has introduced a new range of Bluetooth wireless networking modules for the building controls industry.
Using Bluetooth Low Energy (BLE) technology, the modules transmit data between heating, ventilation, air conditioning and refrigeration, lighting and other building control equipment. The new Bluetooth range is designed for space-restricted areas or if building structure hinders the installation of cable solutions.
The range includes a two-input/output module, four input module, R232 interface for RDM controllers and a battery-operated temperature probe. All these devices connect to a central access point, that then links to RDM’s leading control system front-end DMTouch. Access point options include PoE, 5v and either DIN or ceiling mount options.
The solution features mesh topology, a significant benefit compared to systems communicating point to point. In a mesh system signals can hop between available devices, bypassing obstacles and creating a more robust and reliable wireless infrastructure. The RDM solution allows for continuous data transmission between powered modules, as often as every 15 seconds.
All of the new RDM Bluetooth modules are compatible with the DMTouch, RDM’s control system front-end when utilising the new Bluetooth access points. Up to four access points can be connected to one DMTouch, allowing for a wide range of coverage across large buildings and multiple floors. One DMTouch is said to be able to support a combined total of 64 Bluetooth devices, increasing the scope and flexibility of RDM’s extensive HVACR control network capabilities.
For flexible installation options, two variants are available. One is designed for DIN rail mount while the other is intended for surface (wall or ceiling) mount. Both can be powered with a 5V power supply, while the surface mount variant supports the option of PoE.
Input/output modules
The Bluetooth range includes two input/output (I/O) modules. One module features four inputs, while the other one features two inputs and two outputs. Both modules can be used to extend or improve the Bluetooth Mesh network resilience, without being used for I/O.
All inputs can connect to a mix of resistive temperature sensors. Each has their own over and under temperature alarm thresholds, associated alarm delay and temperature offset option. Alternatively, they can be used as digital on/off volt free inputs, for example, when monitoring plant faults. If monitoring refrigeration equipment, the inputs can also be used to prevent alarms when on defrost mode by mixing temperature inputs and volt free defrost signals.
The two relay outputs are controlled via the DMTouch using either a GP Timer Channel or a TDB programmable logic control program. They are volt-free in operation and provide both N/C and N/O contacts.
RS232 to Bluetooth interface
This module connects to any RDM RS232 controller equipped with Bluetooth solution and provides wireless communication with the DMTouch via the Bluetooth network. The controller will appear as a device on the DMTouch with similar capabilities to RDM’s standard IP connections.
Bluetooth temperature probe
The probe transmits temperature readings to a DMTouch every 10 minutes, going to sleep between transmissions to conserve battery life. In the event of a connection loss the probe will log data at 10-minute intervals for up to a week. Transmitting the data when a connection to DMTouch is restored.
A mobile app for Android and iOS, allows for a temperature offset to be adjusted for calibration purposes. Programming and a battery voltage check can also be carried out via the mobile app. A user replaceable battery further simplifies maintenance of the battery temperature probe.
