Analogue Input Module Offers Decentralised Interface for Building Automation
- Published: Wednesday, 19 June 2013 08:31
The new Dupline® analogue module enables control systems to interface in a decentralised manner with environmental sensors in smart building systems. They can be used in conjunction with any type environmental sensor with a 0-10V or 10K3 output. Typically the addressable device is installed behind the environmental sensor and wired by simply looping the 2 wire bus cable from sensor to sensor. Many sensors can be networked together in this way back to a Dupline® Gateway device, where all the sensor information is available to the BMS via a Modbus serial or TCP connection.
This provides a considerably simpler solution than traditional parallel wiring, where each signal needs a separate connection back to the BMS outstation. The multi-drop approach reduces the number of BMS outstations required and provides greater flexibility for last-minute changes and future modifications. Using Dupline® radically increases the operating distance and I/O capacity of HVAC controllers: this enables solutions to be implemented with fewer sub-panels, further reducing the cost and complexity of installations.
Initially three modules are available, offering up to 4 analogue inputs each with 8-bit resolution. All come in compact 50 x 30 x 18mm packages, ideally suited to decentralised installation inside wall boxes or within environmental sensor housings.
The G88106265 provides three analogue inputs and requires a DC power supply (10-30V). Typically a 4 core cable is installed to carry the power and Dupline® bus to the environmental sensor, where CO2 + Temperature + Humidity information is retrieved before transmitting it back to a HVAC controller over the Dupline® network.
Model G88106311 provides a 10K3 thermistor input and 1-11KΩ variable resistor input along with two 0-10VDC analogue channels. Thermistor accuracy is better than 0.5°C ±1 Analink bit over the full 0-50°C range, whilst the potentiometer is rated better than 1% ±1 Analink bit. As with the G88106265, it is DC powered and can be installed with Dupline® and DC power running in a 4 core cable.
The bus powered G88106312 model offers the same thermistor/potentiometer combination as the G88106311, and would typically be installed behind room temperature sensors with or without set point adjustment. As the device is bus powered installation cost with respect to wiring is very economical.
All the new decentralised analogue input modules operate over the 0-50°C temperature range and are protected against dust and moisture ingress to IP20. They carry CE marks and are cULus approved according to UL60950.