A 12-story office needs 8 AHUs integrated into a Honeywell BMS. Lacking temp feedback, AO modules, and fast freeze protection, the conventional PLC+gateway approach is complex. The BA190 replaces both with native BACnet/IP, modular I/O, and local logic—cutting cost, setup time, and failure points.
Case Details
Scenario
- A 12-story office building with 8 fresh air handling units (AHUs) needs to be integrated into a Honeywell BMS. Site conditions:
- Control panels have only DO for start/stop, no supply/return air temperature feedback.
- Water valves are 0-10V actuators, but no AO module available on site.
- Floor-by-floor power meters use Modbus RTU; energy data must be brought into the BMS for cost allocation.
- When a freeze thermostat trips, the fan must stop and the water valve close within 100ms – this cannot rely on the network.
Conventional approach: PLC + BACnet gateway. Two devices, two software tools, two debugging efforts. If the gateway mapping table doesn’t match, you have to modify code on site.
The BA190 solves it with a single device.
Why BA190
- Native BACnet/IP uplink: Device ID, object instances, COV subscription are all native. The BMS discovers the device automatically – no gateway required.
- Modular I/O: 1 to 3 I/O boards, flexible combination. This AHU needs: 2 AI (PT1000 supply/return air temperature), 1 AO (0-10V water valve), 4 DI (freeze thermostat, filter differential pressure, manual/auto mode, fault alarm), 1 DO (fan start/stop).
- Built-in logic independent of the host: Freeze protection interlocking runs locally on the device, responding in milliseconds even if the network fails.
Real-World Benefits
- Hardware cost: PLC+gateway→ BA190 – save over 70% .
- Labor hours: 1 day for PLC programming + 0.5 day for gateway configuration → 2 hours of web-based configuration.
- Failure points: Eliminates one gateway; fewer protocol conversions, easier troubleshooting.
When to Use BA190 (Replaces "PLC + Gateway")
- You have DI, DO, AI, AO that need to be brought into a BACnet/IP network.
- You need local interlocking (freeze protection, differential pressure, liquid level).
- You have Modbus instruments (power meters, water meters, energy meters) that need to be converted to BACnet.
- You want to reduce device types and shorten on-site commissioning time.
- If you also need to send data to the cloud (MQTT/OPC UA/Modbus TCP), choose the BA190Pro.
Tell us your I/O requirements and we will help you select the right Y series module combination. We look forward to discussing your next project.
