Chiller plant
Modbus integration
Supply and return temperatures, run status and alarms from chiller controllers, pumps and cooling towers, collected over Modbus so the engineering team sees downtime as it happens.
THE PROBLEM
A chiller trip is usually reported by a guest or a tenant
A chiller plant is several machines working together: chillers, primary and secondary pumps, cooling towers and their fans. Each chiller controller tracks leaving and entering water temperature, compressor status, load and an alarm history. That information often stays on the controller screen in the plant room.
When a chiller trips after a power dip and does not restart, the first sign is a warm lobby or a ward that will not cool. The engineering team is then measured on how quickly it responded, with no record of when the fault actually started.
Reading the controllers over Modbus gives a time-stamped record of every stop, restart and alarm, plus the temperatures that show whether the plant is keeping up with load.
HOW WE SET IT UP
The whole plant on one screen
Chiller controllers
Most chiller controllers offer Modbus RTU or TCP directly or through a communication card. We read leaving and entering water temperatures, run and alarm status, and load where available.
Pumps, towers and meters
Pump and tower fan VFDs and the plant energy meters join the same gateway, so the picture includes the auxiliaries that often cause the trip.
Downtime and response time
Every stop and restart is recorded with its time. RIOD Live alerts the duty engineer and keeps the record of how long the plant was down and when someone acted.
Planned with your BMS team
Where a BMS already reads the chillers, we agree the protocol, master or slave role and network separation with the BMS contractor and your IT team before connecting.
FROM THE FIELD
Where we have done this
Taj Hotels: chillers and air conditioning
We monitored power and run status on chillers and AC units so the engineering team could see downtime as it happened and track how quickly maintenance responded, instead of learning about a failure from a guest.
AT A GLANCE
Chiller plant integration in brief
- What is read
- Chilled and condenser water temperatures, run status, alarms, load where available, plus pump and tower drive values
- Hardware
- RS485 Modbus IoT gateway, Modbus RTU over RS485 and Modbus TCP over Ethernet, master or slave
- Connectivity
- Ethernet, Wi-Fi or 4G, chosen per site. MQTT over TLS 1.2
- Power
- 12 V adapter from the panel supply, in a plastic, metal or custom enclosure
- Where data goes
- RIOD Live, or your own server, with API access, PDF and Excel exports with audit trails, and AI access through MCP
- Reports
- Downtime and maintenance response history, PDF and Excel with audit trails
- BMS integration
- Protocol, network and cybersecurity reviewed with your BMS contractor and IT team as part of the project
FAQ
Questions buyers ask us
Can chillers be monitored over Modbus?
Yes. Most commercial chiller controllers offer Modbus RTU or Modbus TCP, either built in or through a communication card. The register map lists temperatures, run status, alarms and often load and run hours.
What should a chiller plant monitoring system show?
At minimum, chilled water supply and return temperatures, each chiller's run and alarm status, and pump and tower status. Adding energy meters shows how efficiently the plant meets the load, and a downtime log shows how quickly faults are handled.
Will it conflict with our existing BMS?
We plan it with your BMS contractor. The gateway can read as a slave on an existing network or connect to a spare port, and the protocol and network separation are reviewed with your IT team before commissioning.
Can we see chiller downtime after a power failure?
Yes. Every stop and restart is recorded with its time, so you can see how long each chiller was down after a power event and when it was brought back.
Want to know the moment a chiller stops?
Tell us the chiller models, what else is in the plant room and whether a BMS is connected. We will propose the points to read and the alerts.