Watlow® F4
ProcessView+ for the legacy Watlow F4
The Watlow F4 is a generation behind the F4T, and chambers running one are usually older than the software that came with them. The controller is not the problem — an F4 that holds setpoint holds setpoint. What has aged is everything around it: the PC, the operating system, and whatever was logging the data. ProcessView+ replaces that layer and leaves the controller alone.
Not sure this is what you have? Large red digits above a smaller green text display, WATLOW at the top left, and a keypad below. The part number on the housing label begins F4. Check compatibility.
On this controller
What ProcessView+ can do with a F4
- Profile control — download, read, start, stop, pause, resume
- Data logging and SQL Server mirroring
- QA reports with per-step tolerance bands
- AMS 2750 uniformity surveys and system accuracy tests
- 21 CFR Part 11 audit trail and signatures
- PID Sets Shared only with the F4T
Not available on this controller
- Autotune
- Analog inputs
- Alarms 5–8 Alarms 1–4 are available
- Open-loop detection
- Variables / remote control
Nothing is withheld. ProcessView+ reads the controller type at startup and shows only what that controller exposes — so these menus do not appear rather than appearing and failing.
- Profile names are limited to 10 characters, against 20 on an F4T.
What you keep, stated plainly
The whole compliance layer works on an F4 exactly as it does on an F4T. That is not a concession — it is how the product is built. Data logging, QA reports, tolerance bands, AMS 2750 uniformity surveys, system accuracy tests, the audit trail and the Part 11 signing ceremony all read from the logging session, not from the controller. They do not know or care which model produced the data.
So the documents your auditor asks for are the same documents, produced the same way, whether the chamber has this year’s controller or one that was discontinued years ago.
You also keep PID Sets, which among the four supported controllers is otherwise offered only on the F4T.
What you do not get, and why
Five capabilities are unavailable on an F4, and it is worth knowing before you buy rather than after:
Autotune, analog inputs, alarms 5–8, open-loop detection, and variables.
None of these are withheld. The software checks the controller type at startup and shows only what that controller exposes — an F4 does not have the analog input channels or the extra alarm channels, so the menus that configure them do not appear. The consequence worth naming: your QA reports will not contain analog-input tolerance rows, because there are no analog inputs to monitor.
One smaller difference: profile names on an F4 are capped at 10 characters, against 20 on an F4T. Long recipe names get truncated, so a naming scheme that fits ten characters is worth settling on early.
The decision this page is really about
If you are reading this, you are probably weighing whether to modernise the software or replace the controller. Worth separating the two questions:
Replacing an F4 with an F4T buys you the five capabilities above, and it is a hardware job with a wiring and re-validation cost attached. Modernising the software around the F4 buys you the data logging, the reporting and the compliance record — the things that are usually the actual reason for the project — and changes nothing physical about the chamber.
For a great many chambers, the second is the whole requirement. If it is not, you will at least know which of the five you are buying the controller for.
See it against your own chamber
The free trial runs against a built-in virtual controller, so you can drive profiles, log data and generate a QA report before connecting anything.
Watlow and F4 are trademarks of Watlow Electric Manufacturing Company. GVE Inc. is not affiliated with, endorsed by, or sponsored by Watlow Electric Manufacturing Company. ProcessView+ is independent software that communicates with these controllers over standard Modbus.