Whistler TRX-2 CPU firmware updater U3.1
========================================

WHAT THIS IS
------------
Whistler's standalone Windows CPU firmware updater for the TRX-2, version U3.1
("CPUUpdater" = Whistler's CPU Update Utility, file version 0.0.1.4, with the
firmware image built in). The executable's build timestamp is 2016-09-26.

No release notes for this version were found. Whistler published CPU change
lists only occasionally, on RadioReference; none names this version.

Whistler's normal update route is EZ-Scan's update check, which downloads and
installs CPU and DSP firmware. Whistler's legacy-upgrade download page
described its standalone updater as a backup "in the event you are having
issues updating your CPU firmware via the EZ Scan software application"; DSP
firmware goes through EZ-Scan (or the separate Whistler DSP Updater).

This is not the newest TRX-2 CPU updater; keep it for downgrading or to
reproduce an older configuration.

APPLIES TO
----------
Whistler TRX-2 base/mobile scanner (US/Canada model).

Must NOT be used on the TRX-2E (international model, own updater), the
TRX-1/TRX-1E, the WS1095/WS1098 (same cabinet, different firmware), or any
other model.

BEFORE STARTING
---------------
- A Windows PC. The updater is a 32-bit Windows program; the Windows versions
  it supports were not stated by Whistler.
- The USB cable supplied with the radio.
- The Whistler USB serial driver installed, so that the scanner appears as a
  COM port. It is installed by EZ-Scan, and is also available as its own entry
  in this archive (id whistler-trx-2-usb-driver-2018-08-20).
- A solid supply: update on the AC adapter or a bench supply, not on a vehicle
  circuit.
- A backup of the SD/microSD card (copy the whole card to the PC) and of the
  programming, made in EZ-Scan.
- Note the current CPU and DSP versions before starting (see VERIFYING).

CONTENTS OF THIS ZIP
--------------------
The zip published on fubsypoly.com wraps the vendor file(s)
byte-for-byte, unmodified.

CPUUpdater_TRX2_U3.1.exe
    696,320 bytes
    SHA-256 4874cb5cf285455efee4bdbf0d11494b1b6434204ec32f1f5a3c8b1bdce70b82
    Whistler CPU Update Utility for the TRX-2, CPU U3.1; PE build timestamp
    2016-09-26.
README.txt
    This file.
SHA256SUMS
    SHA-256 checksums of the files above.

INSTALLATION
------------
 1. Close EZ-Scan and any other program that uses the scanner's COM port.
 2. Run the updater (a standalone Windows program; nothing is installed). Its
    first screen is a licence text with a checkbox, "I acknowledge that I have
    read and agree to the above terms", and a Continue button.
 3. The next screen, headed "IMPORTANT!!!", asks the user to confirm that data
    can already be transferred between the scanner and the PC over the USB
    cable, and ends "Are you ready to proceed with this update utility?".
 4. With the scanner switched off and the USB cable unplugged from it, hold
    down the scanner's MENU key and attach the USB cable to the scanner. The
    updater's own text: "While holding down the scanner's MENU key, attach the
    USB cable to the [scanner]. The scanner will enter its 'CPU SW Upgrade'
    mode."
 5. In the list on the right, select the COM port Windows assigned to the
    scanner (Device Manager > Ports shows it).
 6. Click TEST. The updater reads the scanner and shows "SCANNER VERSION: x.y"
    and "UPDATER VERSION: x.y". "SCANNER VERSION: -none-" means the scanner
    currently holds no CPU application (for example after a failed update);
    the update can still proceed.
 7. If the file is the same as or older than what the scanner holds, the
    updater asks "Do you really want to upload version x.y?". Answer only if
    that is intended.
 8. Click UPDATE. A progress bar runs. On success the updater shows "Operation
    complete. You may exit this utility by clicking the 'EXIT' button."
 9. Disconnect USB, power the scanner on normally and check the version.

The step wording above is taken from the text strings inside the updater
itself; the exact screen layout was not seen and may differ slightly.

VERIFYING
---------
The updater's closing text: "You can check the new version number by pressing
'3' while the scanner's power-up Welcome Message is displayed." RadioReference
owners of the TRX series describe holding MENU at the welcome screen to show
the CPU and DSP versions; the two methods may belong to different firmware
generations, and which one a given radio honours could not be confirmed. EZ-
Scan also reports the model and firmware versions when it connects to the
radio.

IF SOMETHING GOES WRONG
-----------------------
- A failed or interrupted update does not normally brick the scanner. The
  updater's own text: "Please be assured that you cannot 'destroy' your radio
  with this utility - if an update operation fails, the scanner's 'Boot' code
  will clean up and prompt you for a CPU load until the operation is
  successful." Re-enter CPU SW Upgrade mode (hold MENU while attaching USB)
  and run the update again from step 4.
- "No data from the scanner. Please retry from step 1" or "Unable to
  communicate with the scanner": the scanner is not in CPU SW Upgrade mode or
  the wrong COM port is selected. Unplug, repeat step 4, re-select the port.
- "Unable to open the port COM<n>": another program (EZ-Scan, a terminal
  program) has the port open, or the port does not exist. Close the other
  program and re-select.
- No COM port appears: the USB driver is not installed or Windows has replaced
  it. The Whistler drivers are unsigned; owners report needing to disable
  driver signature enforcement on Windows 10/11 before installing them (see
  the USB driver entry in this archive). Only the serial half of the scanner's
  composite USB device needs the driver; the card-reader half mounts without
  one.
- Wrong model: every Whistler updater carries the warning "This software is
  intended only for use with a specific Whistler model. Attempting to update
  any other brand or model scanner with this software/firmware may cause the
  scanner to stop functioning." The community GREFwTool documentation
  describes the result: the bootloader erases the application firmware and the
  radio powers up only in CPU update mode until correct firmware is loaded.
  Recovery is to load the correct updater for the model (and loader) in CPU SW
  Upgrade mode.
- To power a handheld off while it is stuck in CPU update mode, GREFwTool's
  notes say to disconnect USB and remove one battery cell.

DOWNGRADING
-----------
The updater permits loading an older version: after TEST it compares versions
and, if the file is older, asks "Do you really want to upload version x.y?"
before proceeding. This is the vendor's own downgrade path. Whistler did not
publish which DSP versions pair with which older CPU versions; note both
versions before changing either, and keep the newer updater at hand to return.

PROVENANCE
----------
- File: CPUUpdater_TRX2_U3.1.exe
- Retrieved from:
  https://cdn.shopify.com/s/files/1/1420/2702/files/CPUUpdater_TRX2_U3.1.exe
- Wayback copy:
  https://web.archive.org/web/20181017191152/https://cdn.shopify.com/s/files/1/1420/2702/files/CPUUpdater_TRX2_U3.1.exe
- Date retrieved: 2026-09-18
- Official page:
  https://web.archive.org/web/20170107173204/https://whistlergroup.com/pages/scanner-firmware-installers-previous-versions
- Status: verified (from the vendor's own host or a Wayback copy of it)

MORE INFORMATION
----------------
- https://scanners.fubsypoly.com/whistler-trx/vol-4/
- Vendor downloads page (Goliad Products, 2026):
  https://whistlergroup.com/pages/downloads
- Reference Library manual:
  https://scanners.fubsypoly.com/library/whistler-trx-1-digital-handheld-scanner-user-guide/

