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Showing posts with label LGB 55028 Decoder Introduction and Programming. Show all posts
Showing posts with label LGB 55028 Decoder Introduction and Programming. Show all posts

LGB 55028 Decoder Introduction and Programming:

First published 11 Jan 2022, updated and revised.

The general rule of thumb, is to operate a new Loco or the Retrofit decoder with its default Address of 3 on a DCC system  first, and prior to making any attempt to program it.

Tested LGB 55028 decoder with Firmware version number 1.5 with the following equipment.

PIKO 35010 Central Station and a PIKO 35011 Navigator operating with Firmware version number 2.20p.

Note for the PIKO 35010 Central Station, placing it into pseudo programming mode was not necessary, able to program as normal. 

Massoth 1210Z Central Station operating with Firmware version number 2.65, and a Massoth 8134501 Navigator operating with Firmware version number 2.20d.

Note for the Massoth 1210Z Central Station, use programming track connection.

Massoth Service Tool version number 3.5.1.109, Massoth 8176001 Service Board, Massoth PC Module 8175101 with operating Firmware version 4.0.

Note for Massoth Service Tool, have created a number of Test decoder templates for the LGB 55028 decoder to verify correct operation when programmed.

Continuous load at the motor outputs 3.0 amps
Load at the light outputs 600 milliamps
Load for AUX 1 – AUX 6* each 600 milliamps
Load AUX + lights (total) 1.8 amps
Maximum total load (total) 4 amps
Maximum voltage 40 volts
Short circuit and overload protection at the outputs for front lights (LV), rear lights (LH), AUX 1 – AUX 6 and at the motor outputs.

* AUX 5 & AUX 6. On both the 55028 decoders in use, an anomaly occurs if the Function Keys F5 (AUX 5) and F6 (AUX 6) are activated, the decoder locks up and ceases to function, requires a power cycle On/Off to restore the decoder to full functionality.

Setting CV's 130*, 131, and 132 AUX 5, and CV's 133*, 134, and 135 for AUX 6 to zero, has no effect to curing the problem.

To solve the problem, disable the F5 and F6 outputs.

By setting the  F5 CV's  282 and 382 to 0, and the F6 CV's 287 and 387 to 0.

Note, if a decoder reset is initiated, the above CV's WILL default back to the Factory Set CV values!


LGB 55028 Decoder top and bottom view.

LGB 55028  pin configurations with the LGB 55529 Interface Board.

LGB 55129 Decoder Interface.


LGB 55529 Interface Board with 10 pin connector.

Navigator  Prog Menu Firmware version 2.20p, dated 9th June 2021.

Refer to the Massoth DiMAX Navigator manual dated  2019.05 Version 2.10, Page 24, 6. Programming for further details.

The observant may well spot that the picture above is a little different from the manual, a few minor cosmetic changes are evident to the screen layouts of Firmware versions 2.20x, they have no effect on correct operation.

From the Programming Menu as per the picture above, no issues to report.

Long Addressing works as it should, combination of CV 1, CV 17, CV 18 and CV 29, the correct values are present.

CV 17 and CV 18 automatically adjust, likewise CV 29 changes value by adding 32 to the previous value.





















CV 50, valid values and parameters.










Massoth Service Tool Decoder Template for the LGB 55028 Retrofit Decoder.

Values displayed are for a Retrofit Decoder.

Reset to  factory defaults with CV 8 = 8.

 Provided  as a reference guide, the complete CV Listing of all the CV's used on the Retrofit decoder.

Values displayed may be different for Factory Installed LGB models, which are configured to specific requirements dependent on the model number.  

LGB 55028 LED Lighting Effects.


Only valid for CV's 112, 115, 118, 121, 124, 127, 129, 130*, 133*.





Additional testing for compliance and compatibility, Bare Bones DCC System consisting of a Arduino R3 clone and a clone 'H' Bridge controller.

No fancy GUI, entering control commands via a command line prompt with the following syntax.

To READ......<R CV Number 0 0>
To WRITE ...<W CV Number Value to Write 0 0>

















Footnote: It appears for the present it is not possible to connect a Home Brew Voltage Buffer to this decoder via the Decoder Positive and Ground connections.


The two meters show, Input Voltage and Capacitor Storage Voltage, upon disconnecting the power to the track, Capacitor Stored Voltage  has no effect, loco stops immediately.

For a later date, and further investigation, will see if connecting directly to outputs of the Bridge Rectifier solves the issue.