ControlsLens ModLens and BacLens: Modbus and BACnet Tools, AI and Brixon

Short answer: ControlsLens makes two tools for building controls technicians. ModLens, a Modbus diagnostic tool for technicians finds and decodes Modbus registers, logs them and shows them live. BacLens, announced as coming soon, maps a BACnet network, recognizes the equipment, draws live graphics, raises alarms and uses AI to explain what it finds. Neither tool is connected to Brixon today. They work well side by side: ControlsLens shows you what the controls are reporting, and Brixon helps you work out what those readings mean on the equipment.

This article describes the ControlsLens apps from their public website, checked on November 2, 2026. Features and prices can change, so confirm on their site before you buy.

Why controls work needs better field tools

Most commercial HVAC problems end up touching the controls. A rooftop unit short cycles, a VAV box will not open, a meter shows a strange number on the BMS. The technician on site often has no point list, an old front end, or no license for the software that was installed years ago. The manual counts registers from 1 when the device counts from 0. The BACnet network has two routers nobody documented.

Field tools that read the network directly save hours on these jobs. ControlsLens builds tools for exactly that situation: one for Modbus and one for BACnet.

ModLens: the Modbus tool

ModLens, a Modbus diagnostic tool for technicians works with Modbus TCP, Modbus RTU over RS-485 through a USB adapter, and RTU over TCP gateways. It runs on Windows 10 and 11 and on Linux, including a Raspberry Pi, and works offline.

What ModLens can do

• Explorer. Read a block of registers and see them as uint16, int16, float32, int32 and uint32 in every common byte order at once. Values that look like real measurements are highlighted.
• Find a value. Type the number shown on a device display, for example a supply temperature of 21.2 °C. ModLens tries every format, word order and common scale across unit IDs and both register tables, then ranks the matches. Change the value and re-check until only the real register stays.
• Scanner. Find Modbus TCP devices on a subnet, the unit IDs answering on a bus or behind a gateway, and which addresses exist in a range.
• Live tags, trends and alarms. Name registers, set units and scaling, and watch them on a trend chart with high and low alarms.
• 24/7 CSV logging and remote dashboard. Leave a laptop or a Raspberry Pi on site, log to daily CSV files, and check values from a phone with a password.
• Plain language errors. Modbus exceptions and timeouts come with a checklist: unit ID, baud rate and parity, swapped A/B wires, address offset, register table and block size.

ControlsLens says each build is tested against the open source pymodbus implementation. Pricing on their site at the time of writing: a 14-day free trial, then a one-time Pro license (launch price $89), a 5-computer Team pack ($349) or a Pi Logger license ($49). A free Lite mode stays available after the trial.

ModLens Sim

ModLens Sim, a free Modbus device simulator turns a PC or Raspberry Pi into simulated controllers, meters and sensors. Values can drift, cycle or replay your own CSV, Excel, JSON or web API data. It is useful to test a BMS integration before the equipment arrives, or to train new technicians without touching live equipment.

BacLens: the BACnet tool (coming soon)

BacLens, a BACnet discovery and troubleshooting tool is announced with a waitlist. Its page describes a laptop tool you connect to a BACnet network, supporting BACnet/IP, foreign device registration with a BBMD, MS/TP over RS-485 and BACnet/SC.

What BacLens is planned to do

• Full architecture. Every BBMD, router, BACnet/IP and MS/TP network and controller, laid out the way the building is wired, with device instance, address and point count.
• Equipment recognized. Points are grouped into AHUs, VAVs, boilers, chillers, pumps and meters, from English and French point names such as TEMP ALIM or POMPE.
• Live system graphics. Graphics are built from the points instead of drawn by hand. Click a value to chart it, or override and release it at a BACnet priority.
• Alarms that explain. Rules run on the recognized equipment: damper open with low airflow, pump commanded but not running, zone too cold. Alarms go by email to the people who chose that alarm type.
• Record and replay. Every value is logged so you can go back to any moment and watch what the system did.
• Network analyzer. BACnet packets decoded in plain words, with response times, retries, duplicate device instances and router rejects, plus export to Wireshark.

The page lists a Free version (network discovery, 20 live points, 1 live graphic, read and override) and a Pro version (every point, all graphics, alarms, recording and the analyzer). Pricing has not been announced. A free BACnet simulator is also available on their site today.

How AI is changing BACnet work

BACnet itself is a communication standard (ASHRAE 135). It defines how devices talk, not how anyone interprets the data. That interpretation has always been manual work: reading point names, guessing which point is the supply temperature, drawing graphics and writing alarm logic one site at a time.

This is where AI fits. Tools like BacLens describe AI that maps points to equipment, explains alarms, edits graphics from plain words and investigates packet captures. The important detail in their approach is that the AI works through the tool's own functions and real values, so its answers come with the numbers behind them. They also offer a local model option for sites that must stay off the cloud, and say the built-in rules still work without AI.

Will AI become a normal part of BACnet tools? In our view it is heading that way, for practical reasons:

• Point naming is messy. Every integrator names points differently, in different languages. Recognizing them is exactly the kind of pattern work AI helps with.
• Fewer people know old systems. Experienced controls techs retire, and their knowledge of each site leaves with them. Tools that explain a building from the network help newer techs get started.
• Secure connections are growing. BACnet/SC brings encrypted connections, which makes remote analysis more realistic for owners who worry about security.

That said, AI does not replace a technician who checks the equipment. A model can suggest that a damper is stuck. Someone still has to look at the actuator, the linkage and the wiring. The best tools will be the ones that show their evidence and admit when they are not sure.

How ControlsLens and Brixon fit together

There is no direct connection between ControlsLens and Brixon today. They solve different parts of the same job, so they work well one after the other:

1. Read the system with ControlsLens. Use ModLens to find the register behind a VFD fault code or a meter value, or BacLens to see which pump is commanded on but not running.
2. Bring the readings to Brixon. Describe the equipment, the values and what you already checked. Brixon helps you work through the free and quick checks first, then the deeper tests, and marks what comes from documentation versus general knowledge.
3. Save the fix for your team. On team plans, solved problems are shared so the next technician on that building starts from what worked.

Example. A rooftop unit trips on high discharge temperature. ModLens shows the drive speed register sitting at a low value while the BMS commands 100%. You ask Brixon: "RTU high discharge temp, condenser fan VFD reads 30 Hz while commanded at 100%, what should I check first?" Brixon suggests checking the drive's speed reference source, the analog signal scaling and the drive fault history before anything more expensive. It can be wrong, so you confirm on the unit.

Technicians who use AI assistants that support MCP, such as Claude, can also connect Brixon through its technician MCP connection on a paid plan. Brixon's free 4-20 mA and 0-10 V signal scaling calculator and VFD speed calculator help check the numbers you read on the network.

Which tool for which job

Bottom line

ControlsLens gives you eyes on the controls network: Modbus today with ModLens, and BACnet soon with BacLens. Brixon helps you turn those readings into a diagnosis, starting with the easy checks. Try the free field tools, or describe your fault to Brixon. Your first question is free: ask Brixon.

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