The Haystack Labs working group has been on a roll. Over the past couple of months, a series of commits to the Xeto GitHub repository have landed meaningful advances across multiple domains — from valve and damper modeling to AC power normalisation to a brand-new proposal for modeling motors and VFDs. Here's a quick roundup.
Valves and Dampers Get a Better Foundation
One of the cleaner architectural improvements in recent weeks is the introduction of Valve and Damper as abstract equipment base types. Previously the type system only really catered for actuated variants; now non-actuated equipment — think check valves or manual dampers — can use the base specs directly. ValveActuator and DamperActuator have been redefined as intersection types (Actuator & Valve, Actuator & Damper), which is both more expressive and more composable. A new thermostatic marker was also added to support self-regulating valves like thermostatic mixing valves.
AC Electric Measurements: Getting Normalization Right
An updated Meters.md document and supporting spec changes tackle something that trips up a lot of implementations: how do you normalise AC power and energy measurements when different manufacturers encode power flow in different ways? The commit introduces clear guidance on net, import, and export conventions for active power, reactive power, and energy — along with minimum value constraints on magnitude voltage and current sensors to establish sensible baselines.
Fan and VFD Points: More Precision
Fan speed control has been tightened up in a way that reflects real-world equipment. There are now two distinct control patterns: enumerated speed (off plus a fixed set of speed levels) and modulating speed (a continuous 0–100% command). A new vfd.xeto file defines VFD output frequency sensors and commands, and DischargeFanSpeedCmd has been renamed to DischargeFanSpeedModulatingCmd to make the intent explicit.
Motors: A New Modeling Proposal
The April 14th working group meeting introduced a working proposal for modeling motors and the power electronics — VFDs, ECM motors — that control them. The core challenge: a VFD and its motor are often in different physical locations, made by different manufacturers, and need to be tracked independently for asset management. The proposal handles this through four scenarios, ranging from a simple flat model up to a single VFD driving two motors. Throughout, Xeto Queries are the key ingredient — they traverse the equipment graph to find the right points regardless of where they sit in the hierarchy.
New Tags: Rotational, Runtime, EVSE, and More
The Mar. 25 commit rounds things out with a set of new marker tags — absolute, bearing, rotational, runtime, vehicle, winding — plus motor sensors for rotational frequency, direction, bearing temperature, and winding temperature. There's also a complete new set of definitions for EV charging infrastructure (EVSE), covering coupler and cable status, port charging states, and DC power setpoints.
Get Involved
All of this is available to review in the Xeto repository. The motor and VFD proposal in particular is still a work in progress, and the working group welcomes input from the community.
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