PID tuning software that does not connect to the plant
Most products in this category sit on the control network, read the historian, and sell a site licence. PIDSnap does not. The input is a photograph of a trend and a faceplate. Nothing is written back. If the trend shows a sticking valve, the session is refused.
What PIDSnap is
A loop is misbehaving. You photograph the trend screen and the controller faceplate from your phone. PIDSnap reads the shapes, reports whether the problem is tuning or something tuning cannot reach, and — if it is tuning — computes the next value to type, in the units on that faceplate. The value is computed from the number you confirmed, not invented by a model.
Pre-flight is free. A paid session is one loop, observation by observation. If the result is mechanical — stiction, backlash, a saturated output — the payment comes back. That is the product, not a disclaimer at the bottom of a quote.
What it is not
- Not a historian-connected CLPM suite. No OPC, no plant network, no overnight scan of two thousand loops.
- Not LOOP-PRO, PlantESP, or a site licence sold against a bad-actor list.
- Not an autotune that invents Kp from a photo. There is no process model.
- Not a closed-loop Ziegler-Nichols wizard. It will not tell you to cycle the loop to find Ku.
- Not a connection to DeltaV, Experion, PCS 7, or a PLC. The only thing that leaves the plant is a picture you chose to take.
Who the other products are for
Control Station and the plant-wide CLPM tools earn their keep when you have a historian, permission to sit on the OT network, and a list of loops to rank. That is a real job. It is a different job. If you need a heat map of every loop on the site, you are not in the wrong shop by accident — you are shopping for a different machine.
If you are standing at a console with one loop that will not sit, you do not need a historian connection to find out whether the valve is sticking. You need the trend in front of you read honestly.
The air gap is the point
A photo cannot write a setpoint. It cannot poll a controller. It cannot be left running against a unit after you have gone home. For a lot of plants that is not a limitation; it is the reason the tool is allowed in the door.
The cost of that choice is that PIDSnap will not watch the loop for you, will not rank the site, and will not fit an FOPDT model while you sleep. The free calculator will apply a named method to numbers you typed. The paid session will not.
When to use which
- One loop, now, no network: PIDSnap. Start at the free check.
- A named method from a bump you already ran: the PID tuning calculator — reference, not a recommendation.
- Plant-wide, historian in, quote-driven CLPM: the tools that live on that network. This is not one of them.