LGB 55021 Decoder Info;

First published 21 Jan 2022, updated and revised.

LGB 55021 Version 2.0 decoder, for DC motor up to 1.5 Amp, LR and LF light functions 200 Ma each, F1 output at 300 Ma.

Notes and observations.:

Information as supplied is for Firmware Revisions 2.50 and 2.80, all documentation is available via the links within this Blog Posting,  can be used as references to other version numbers.

CV 1 short address to 127, Long Address available using CV 17 and CV 18, and changing  CV 29 Bit  5 ON.

Decoder Reset, is initiated by using CV 6 = 55 and CV 5 = 55 in Register Mode via the Navigator (PIKO/Massoth) Handsets, connected to a Massoth 1210Z Central Station using the programming track.

Register Mode only required for a Decoder Reset, other CV's can be Read or Write to as normal.

The PIKO 35010 Central Station is unable to carry out the instructions for a Decoder Reset, even though the Navigators will indicate that a Reset is successful, a decoder Read Back will show that the original values have not changed.

A work around is to use the Navigator Change Address Screen, which can be used to Set the address back to 3, will also re configure CV 29, as there are so few CV's to change, use the CV Write/Read screen to change the remaining CV's.

Massoth Service Tool, is unable to activate a Decoder Reset in Register Mode, a Reset by using CV 55 = 55 has also been disabled, and has been removed from the updated Decoder Template.

Recreated a new updated Massoth Service Tool Template, which is used to Write the correct CV Values to the decoder, as if carrying out a Decoder Reset. 

There are  a few variances in the default values for CV's in versions 2.50 and 2.80.

Version 2.80, CV 29 will default to 28 speed steps, CV 2 to 0, and CV 61 to 0.

Both CV listings are available as downloadable links for comparison.

CV 54 will default to 2 on a Reset, Load Monitoring ON, CV 54 is also used to set the F1 output to flashing  by adding 16 to the value.

Note, CV 49 and CV 50 will default to 32,  maximum available track voltage.

LGB 55021 Decoder top view with connections marked.

LGB 55021 Decoder lower view.

The Orange Wire, connects as shown, little known feature to use the F2 Function Output.

Original English only version of the  decoder manual, for comparison and reference to the documentation contained within this Blog Posting. 

Original decoder template from Massoth Service Tool.

Revised Massoth Service Tool Decoder Template:

CV settings for decoder with Firmware Version 2.50.

CV settings for decoder with Firmware Version 2.80.

LGB 55021 decoder version 2.50 list of CV's and descriptions, including notes for Decoder Reset.

LGB 55026 pin interface.

Connections to a Modified Servo Tester.

Connections to NE555 Servo Controller.

Using the LGB 55021 F1 Output to operate a Servo.

Using the LGB 55021 F1 Output to operate a Relay, with connections to a Power Storage Device.