SDS200 Firmware Update Change Log

All firmware updates are done using Sentinel. Select Update --> Update Firmware

Before applying updates, you should back up your programming. Always use the latest version of Sentinel to update.

1.27.00 Main (11/06/2026)

New Features and Improvements

• OTA alias support: Added support for Motorola and Harris P25 over-the-air (OTA) aliases.
• DMR enhancements: Added support for DMR Tier 3 OTA aliases.
  • Note on Aliases: Aliases are human-meaningful names that may be assigned by agencies to specific radios. These complement the Unit IDs, which are just unique numbers used to identify radios.
• Location Control: Fixed an issue that occurred when scanning a single site.
• Unit ID management: Fixed duplicate Unit ID registration in Sentinel's/Scanner's System "Unit ID" menu.

OTA Alias Reception Requirements

• If aliases do not appear on certain trunked systems, the scanner is not necessarily malfunctioning. All the following conditions must be met for the SDS200 to receive and display OTA alias data:

1. Configure the display. The customizable display layout must include the "Unit ID Name" field. If the field is not present in the active layout, decoded alias text will not be visible.
2. Account for saved aliases. Aliases are saved automatically. Stale aliases are not updated, and previously alpha-tagged Unit IDs are not overwritten.
3. Confirm system-side broadcasting. The monitored trunked network must actively transmit alias data. Some public-safety agencies disable OTA Alias broadcasting or limit it to dispatching consoles. If the system does not transmit the data stream, the scanner has nothing to decode.
4. Verify signal quality. OTA Alias data blocks require a clean, high-quality RF signal. Weak reception or a high bit-error rate (BER) can prevent successful decoding. Under these conditions, the SDS200 prioritizes voice packets and may drop the limited sub-audible data packets that carry the alias text.

Technical Note: P25 Phase 1 and Phase 2 OTA Initial Alias Behavior

• With OTA Talker Alias support enabled, initial aliases may appear at different speeds depending on the P25 system type. This is expected behavior caused by differences in the P25 air-interface protocols, not a scanner defect. Captured aliases are instantaneously displayed.
• P25 Phase 1 (FDMA): The system assigns a dedicated 12.5 kHz channel to one conversation. Link Control Words (LCWs), which contain the Unit ID, are interleaved directly into each voice superframe, approximately every 180–360 ms. Because this data is transmitted continuously, the SDS200 can usually decode the alias almost immediately, even when it joins a transmission already in progress.
• P25 Phase 2 (TDMA): The system divides the same channel into two alternating 30 ms time slots. This reduces the space available for sub-audible signaling. Instead of a continuous inline stream, Phase 2 uses a Slow Associated Control Channel (SACCH), which packages and updates alias data over a longer interval. As a result, alias text may take noticeably longer to appear.

1.26.01 Main (03/27/2026)

• Added Type option to the P25 Manual Band Plan.
• Enabled Slot Selection option for DMR OFT frequencies.
• Improved late entry reception for DMR Capacity Max (Tier 3).
• Improved active channel reception for DMR Capacity Plus.
• Updated DMR RAS information detection, control, and management.
• Improved display of incorrect TGIDs for RAS-enabled DMR.
• Fixed an issue where P25 Phase 2 would remain on the voice channel when two slots were filled.
• Fixed a reception issue when a voice frame was present in another slot on the DMR control channel.

1.24.00 Main (12/20/2025)

• Fixed an issue where the P25 Integrated Voice & Data control channel was incorrectly recognized.
• Fixed an issue where a click sound could be heard when displaying "LINK" in P25 Conventional mode.
• Fixed an issue when receiving ProVoice.
• Fixed an issue with control channel handoff.
• Fixed an issue where channels with a positive volume offset would not mute at volume 0 when receiving digital data.

1.23.20 Main (10/17/2025)

Requires SUB V1.03.15 or later.
• Resolved an issue where NAC information was not activated in System Status mode.
• Enhanced squelch sensitivity and control for WFM/FMB modes. (with Sub)
• Fixed a bug where NAC was not displayed during P25 Phase 2 voice transmissions.
• Corrected an issue where mute was released even without a tone after receiving a Tone Out signal.
• WX Alert and SAME Decoding Performance Improved.
• Removed "Bearcat" at startup screen to align with model name consistency.

1.03.15 Sub (10/17/2025)

Requires Main V1.23.20 or later.
• Improved WFM/FMB Squelch Threshold Adjustment. (with Main)
• Resolved an issue where no audio was output during P25 voice decoding on P16 3600 baud systems.

1.23.15 Main (03/24/2025)

• Supports DMR Tier 3 Multi-Block VCH Grant.
• Improved to detect DMR Tier 3 Capacity Max late entry messages.
• Added Weather EAS event codes: SQW, BLU

1.03.06 Sub (7/11/2024)

Increased audio level in Waterfall AM mode. Nothing else has been changed.

1.23.07 Main (3/22/2024)

• Fixed an issue where the P25 Phase 2 NAC was not displayed correctly on voice channels.

1.23.05 Main (2/2/2024)

This firmware applies the following bug fix:

• Fixed a bug in Waterfall mode where the IF polarity was switched at a specific frequency and the carrier was displayed on the opposite side.

1.03.05 Sub (1/19/2024)

This firmware applies fixes for the following issues:

• Fixed the reception issue on Motorola Type II sites.
• Fixed an issue where there were spots where no received audio was heard when moving the marker in waterfall mode.

1.23.03 Main (12/28/23)

This firmware applies the following enhancements and bug fixes:

• Fixed that disabled RECORDING when entering waterfall mode.
• Fixed an issue where the Signal Bar and RSSI would not be displayed when a weak signal was received.

1.03.02 Sub / 1.23.01 Main(12/21/23)

This firmware applies the following enhancements and bug fixes:

• Support Waterfall
• (Latest version of Sentinel (2.05.03) required to use these features).
• Improved digital reception performance. The improvement effect varies depending on the receiving area.
  
  • Fixed the problem of P25 Phase2 Unit ID not being detected.
  • Improved P25 Phase2 signal detection rate.
  • Improved P25, DMR, NXDN OFT signal detection rate.
    
  • Updated Filter for P25 Phase1, DMR, and NXDN.
    
  • Increased the speed of digital scanning.
    
• Improved accuracy of the reading for RSSI and the number of signal bars. The current readings are more accurate than previously were across all bands. The firmware update that implements the Waterfall Feature did not affect the sensitivity of the radio. In some cases, the new RSSI and signal bar readings may be very different than they used to be, creating the erroneous impression that the scanner is not performing as well as it did previously.
• SDS200 Waterfall Feature Operation Manual

1.21.00 Main (6/29/2022)

This firmware applies the following enhancements and bug fixes:

• Added 2.5 kHz and 3.125 kHz steps to the Custom Search and Discovery mode.
• Housekeeping update to accommodate revised hardware.
• (latest version of Sentinel (2.03) required to use these features)
  

1.10.00 Main (4/15/2019)

This firmware applies the following enhancements and bug fixes:

• Fixed the issue of false TGID displaying during site hold.
• Modified the valid condition of EDACS system ID.
• Improved DMR OFT reception.
• Improved NXDN48 (OFT) reception.
• Slightly improved the clarity of analog and digital voice

1.09.02 Main (4/5/2019)

This firmware applies the following enhancements and bug fixes:

• Fixed the issue of stopping scan during priority scan.
• Fixed the issue the open squelch backlight does not turn off till hold time expires
• Changed housekeeping off while scanning one site and detecting its control channel (drop in reception every 2 seconds).

1.02.01 Sub / 1.08.05 Main (3/7/2019)

Be sure to also update Sentinel when applying this update.

This firmware update applies the following new settings and bug fixes:

• Added an "AMP OFF Timer" setting that determines how long the amplifier stays on after a transmission ends. If you hear hum between transmissions, change this from Infinite to one of the available settings.
• Added "Wide Normal", "Wide Invert" and "Wide Auto" filter options for FM performance improvement. When you pick this setting, the filter becomes weaker for interference on a nearby frequency. However, the linearity of the IF can be maintained even when there is strong interference within the band, and the reception may be improved in some cases.
• Added an option to display the filter setting when customizing the display.
• Improved a reception dropout issue where dropouts are often accompanied by "LINK" icon appearing at start of dropout.
• Improved crackling noise on analog.
• Improved the reports that some REC files created have no audio captured at replay.
• Added a prompt to exit certain modes.

1.02.00 Sub / 1.07.04 Main

First release firmware adds additional countermeasures to help in strong signal areas (especially for VHF/UHF). It also adds a user option to set the default RF High Pass Filter (HPF) used.

MENU --> SETTINGS --> GLOBAL AUTO FILTER

• Normal (always use HPF)
• Invert (always use inverted HPF)
• Auto (try HPF then if no signal detected to open squelch, try inverted HPF)

Note: If Auto is selected, conventional scan and search speed will be greatly slowed, as every frequency on which a signal is not detected on first pass will be rescanned using the inverted HPF setting.

MENU --> MANAGE FAVORITES --> REVIEW/EDIT SYSTEM --> EDIT SITE --> SET FILTER (Setting menu for trunked systems)

• Global (use the setting from GLOBAL AUTO FILTER)
• Normal
• Invert
• Auto

MENU --> MANAGE FAVORITES --> REVIEW/EDIT SYSTEM --> EDIT DEPARTMENT --> SET FILTER (Setting menu for conventional systems)

• Global (use the setting from GLOBAL AUTO FILTER)
• Normal
• Invert
• Auto

MENU --> SRCH/CLOCALL OPT --> SET FILTER (Setting menu for Close Call and Search)

• Global (use the setting from GLOBAL AUTO FILTER)
• Normal
• Invert
• Auto