A month ago, we worked with a building automation integrator on an HVAC digital upgrade for a commercial office building built in 2005. The site was a textbook case: the AHU and FCU control signals were dry contacts (DI/DO); the chiller plant had 4‑20 mA pressure transmitters and PT100 temperature sensors; plus several third‑party power meters that spoke only Modbus RTU. The building’s BMS core controller, however, was a well‑known BACnet/IP device – all data had to be delivered over BACnet/IP.
The old‑school approach would have meant a BACnet gateway for Modbus conversion, a separate remote I/O module for DI/AI, and yet another protocol converter for the meters – a costly, space‑hungry, and time‑consuming mess.
That’s when we introduced them to the BA190Pro. What really stands out is that it’s a native BACnet/IP server that can also speak Modbus TCP, OPC UA, or MQTT as uplink protocols – effectively “translating” non‑BACnet devices into standard BACnet objects that the BMS can read and control directly.
For this project, we chose three Y‑series boards: a Y11 (8 DI) for fan running status and auto/manual states, a Y31 (4 AI) for two 4‑20 mA pressure transmitters and two 0‑10 V valve feedback signals, and a Y51 (2‑channel PT100) for supply and return water temperatures. All three plug into the BA190Pro, bringing the total width to just 40 mm – it snaps right onto the DIN rail in the telecom closet, powered by 24 VDC from a nearby fan control panel. Very tidy.
What impressed the integrator’s engineering team most was the BA190Pro’s BACnet object mapping. In the web configuration page, every installed I/O channel automatically generates the corresponding BACnet object: DI → Binary Input, DO → Binary Output, AI → Analog Input, AO → Analog Output. Instance numbers are assigned sequentially. For example, the first AI channel on the Y31 becomes Analog Input 0, backed by Modbus address 3000. No complex programming – just connect to the BACnet network, and all data points appear instantly.
We also connected a Modbus RTU power meter to the BA190Pro’s RS485 port. A few clicks in the “Modbus Settings” page let us poll voltage, current, and active power into internal registers. Those registers then automatically appear as BACnet objects as well. From the BMS perspective, everything looks like native BACnet data – no need to worry about whether it’s local I/O or a serial meter.
The no‑code logic control feature was another pleasant surprise. One requirement: when return water temperature exceeds 55 °C and pressure drops below 2 bar, automatically shut down a set of fans and trigger an alarm via DO. Traditionally, this would require writing logic in the central controller or a DDC. With the BA190Pro, we simply configured a “numeric logic” rule on the web page – select the AI channel (return temperature), choose “greater than”, set the threshold to 55, combine it with a second condition (pressure < 2 bar), and point the output to a DO channel. All dropdowns and value fields – no code at all. Even if the central controller loses network connectivity, the BA190Pro executes local interlocking independently, greatly improving system reliability.
The dual Ethernet ports also proved valuable in this retrofit. We connected ETH0 to the main BMS switch and daisy‑chained ETH1 to another BA190Pro on the floor below, forming a star‑free topology that saved switches and extra cabling. If one node fails, the built‑in bypass mode automatically maintains the link.
Finally, BLRAT remote access. After commissioning, the integrator’s technician securely accessed the field device’s web interface via BLRAT to remotely adjust the AI scaling and offset values and even update the firmware – all without a site visit. For multiple nodes spread across different floors, this remote maintenance capability is a game‑changer.
The BA190Pro BACnet/IP EdgeIO Controller is not meant to replace an existing building control system – it’s a “universal access point” for BACnet networks, bringing third‑party devices, aging sensors, and serial instruments into unified management with minimal effort. For system integrators, it adds a reliable, flexible, and cost‑effective tool to your toolbox when facing diverse signals in retrofit or new construction projects. If you spend your days working with Honeywell, Siemens, Johnson Controls, or other BACnet systems, give the BA190Pro a try next time you encounter non‑standard signals or Modbus devices. It won’t steal the spotlight – but it will quietly solve a lot of your headaches.
