Two systems that would not talk to each other.
The head office of a national retailer in Ottawa had motorized blinds that were meant to follow the sun. After several attempts, the contractors, the supplier and the design engineer could not connect them to the building automation system. Shokri Elhoussini, P.Eng., now EEB’s founder, found where they could meet.
The problem
The design called for the blinds to open and close automatically on signals from photocells outside the building. Closing them at the right time keeps glare and solar heat out; opening them lets daylight in. That serves two purposes: comfort for the people inside, and a lower cooling and heating load on the HVAC system.
The blinds and the BMS came from different suppliers. The contractors, the blinds supplier and the engineer tried several times to connect them. Each attempt failed, and the blinds could not respond to the photocells as the design intended.
The approach
- Reviewed both systems in full. We went through the components of each system, its software and its configuration, instead of looking only at the point where the connection kept failing.
- Looked for a common platform. The question was where both systems could exchange signals in a way each one already understood.
- Found the tie-in point one level up. Both systems could be joined at their main communication panels, before communication branches out to the individual subsystems.
- Directed the connection. The technicians made the connections we specified, and the system was rebooted.
The result
When the system came back online, the blinds were fully connected to the BMS and operated as the engineer designed: opening and closing on the photocell signals, for comfort and HVAC optimization.
When each supplier says the problem is on the other side, the answer is often one level up, where both systems already talk.
Two systems, one stubborn problem?
Integration gaps between suppliers are common in controls, HVAC, electrical and process equipment. Tell us what will not work together.