QuadLN_S LocoNet Servo Decoder Family

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2024 Marks the 10th Anniversary of the QuadLN_S! Firmware version 3.3.2 is now released plus there is a new Signal Connector Board. See Latest News .

The QuadLN_S family starts with the QuadLN_S LocoNet® Servo Decoder. This board supports up to 16 servos (and now stall motors too) and has 8 configurable input/outputs. The QuadLN_S Detector Board add-on provides 4 channels of current detection. The QuadLN_S Signal Board add-on provides 24 LED drive outputs with realistic prototype effects. The QuadLN_S Remote Align Board offers simple servo alignment, detector sensitivity adjustment and signal LED brightness adjustment. The system can be easily configured to your specific needs using JMRI.

Some Common QuadLN_S Configurations

The QuadLN_S LocoNet® Servo Decoder

The QuadLN_S LocoNet® Servo Decoder is the heart of the system and handles servo control, inputs, outputs and LocoNet® communications. Provides complete turnout control of up to 16 compact SG90 servos. Supports stall motors via optional Driver boards. Optional add-on boards for Detection and Signaling. Fully configurable using JMRI. Operates on a conventional LocoNet® with a command station or on a standalone LocoNet® that has no command station. Firmware updates performed using JMRI (Remote Align board required to initiate a firmware update).

QuadLN_S LocoNet® Servo Decoder Features

  • Operate turnouts from your control panel, throttle, or JMRI.
  • Supports up to 16 Servos per board with version 3 firmware.
  • Now supports Stall Motors with version 3 firmware and new Driver board
  • Supports 8 Servos + 8 configurable input/outputs
  • Each input/output can be both an external input and a servo position indicator output at the same time.
  • Use pushbuttons, toggle switches or external logic from other boards as inputs.
  • 2-position (turnout) and 3-position (semaphore, 3-way stub) servo control.
  • Local inputs can be locked out via (key)switch or LocoNet command. Perfect for continuous running during open houses.
  • Turnout Position feedback reporting over LocoNet® to confirm commands are received and acted upon.
  • Cascade feature allows aligning an entire yard ladder by throwing just one turnout.
  • 8 Programmable routes for triggering Turnouts, Sensors and Signals.
  • Locally adjust servo parameters using the Remote Align board or set them via JMRI.
  • Easily configured using JMRI.
  • Separate Closed and Thrown speed settings for animation of features like a pile driver – slow going up but fast going down.
  • Oscillate mode for easy animation of features like pump heads or wig-wag signal arms.
  • Detector Board add-on for 4 channels of current detection with individual sensitivity adjustments.
  • Signal Board add-on for 24 LED outputs with realistic effects.
  • Field upgradeable firmware (requires Remote Align board and JMRI).
  • So much more – download the QuadLN_S manual plus the Signal Board and Detector Board manuals for all the information (see below).

QuadLN_S Detector Board

The QuadLN_S Detector Board add-on provides 4 channels of current detection with individual channel sensitivity adjustments. Includes 4 detectors mounted on their own boards with screw terminal for easy wiring.

QuadLN_S Detector Board Features

  • Plugs in the QuadLN_S Main IO port.
  • Provides 4 detection channels.
  • The QuadLN_S reports changes in the state of each detector to JMRI using LocoNet® Sensor messages.
  • Uses current transformers to detect block feeder current without any electrical connection to DCC.
  • Each current transformer comes mounted on its own small PC board with screw terminals – no soldering under the layout required!
  • The block feeder wire just passes straight through the center of the current transformer (no loops).
  • Simple wiring – hook up the current transformer to the Detector Board using a twisted-pair wire (CAT3 or CAT5 ethernet cable works fine).
  • Individual sensitivity adjustment for each detection channel using the Remote Align board or JMRI.
  • Two sensitivity ranges with 32 levels in each range
  • Utilize any spare detector channel as a general Main IO line.
  • The QuadLN_S Detector Manual has all the details! (download manuals below)

QuadLN_S Signal Board

The QuadLN_S Signal Board add-on provides 24 LED outputs and realistic effects for Searchlights, CPL signals and crossings.

QuadLN_S Signal Board Features

  • Plugs into the QuadLN_S Exp IO port.
  • Provides 24 LED outputs.
  • Any mix of common cathode, common anode and 2-lead bicolor LEDs.
  • Standard 3 pin headers with Output, 5V and Ground for easy wiring with servo extension cables.
  • Searchlight transition effects.
  • CPL semaphore effect.
  • Realistic fade.
  • Flashing aspects are handled locally by the QuadLN_S with proper flash rates, eliminating Loconet traffic jams when trying to have JMRI constantly flash signals.
  • Proper Grade crossing flash rate along with cross fade that makes your crossing look like the prototype back when bulbs were used.
  • Software brightness adjustment for each LED output.
  • Built-in 330 ohm resistor in each LED output eliminates the need for external resistors in many cases.
  • On-board mounting points to add your own resistors when a lower resistance value is required.
  • Up to 48 signal aspects can be defined to provide prototypical signaling.
  • Each aspect can control up to 4 LEDs.
  • Aspect control is very flexible and each aspect can be configured for control by Signal Mast messages, Turnout messages or Sensor messages.
  • Signal wiring breakout board available with screw terminals or solder pads.
  • The QuadLN_S Signals Manual has all the details! (download manuals below)

See the individual product pages for more information on each board or download the Version 2 or Version 3 packages below and get the manuals for all 3 boards.

More Info

QuadLN_S at the NCMRS

John Burrow of the NCMRS did a great video that explains the QuadLN_S and how they use at their club.

QuadLN_S with Standalone LocoNet®

Not using Digitrax? See how Jeremy Brown added a Standalone LocoNet® to fully utilize the QuadLN_S with his NCE system here: Santa Fe High Desert Division Stand Alone LocoNet

Animation using QuadLN_S special features

The QuadLN_S is not just for turnouts! Check out some amazing animations in these videos:

Pile Driver Animation By Dick Roberts MMR

Wig-Wag Signal Animation By Keith Ruberson

QuadLN_S is available pre-configured for non-Loconet users

The QuadLN_S can come pre-configured for 8 servos and 8 inputs for fascia controllers or pushbuttons. Contact us for more information.

User Support Groups

Tam-Valley-Products@groups.io is the forum for QuadLN_S questions and discussion.

jmriusers@groups.io is the place for all things JMRI.

Firmware Updates and Manuals

See the Downloads Page for the latest firmware and manuals.

JMRI QuadLN_S decoder template showing the main configuration tab.