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CAN-GC3 CANBUS DCC Command Station


Copyright Peter Giling

To complete the D-connector type set of CANBUS Pcboards, this is the DCC Command Station.
It features all that is on the original CAN CMD, but with a few firmware and hardware adaptions to easy interconnect with CAN-GC1 and CAN-GC2.
The CANBUS CAB1 is 100% compatible to be used with this programmer.
The slightly larger CAN-GC5, without SMD parts is available now.

Important changes

CBUS Loco direction flag has been changed!

starting with revision 8778 the loco direction flag is corrected to match the DCC-NMRA standard.
Please swap the loco placing before running in automatic mode after you updated Rocrail to 8778 or higher.



  • Separate supply not needed. That is already available from CAN-GC1.
  • It is possible to use CAN-GC3 as stand alone with a 15V dc supply, together with CAN-GC5V2.
  • All connections and Leds in front, for easy build in your own housing.
  • Booster output. RJ12 connector for connection of ORD-3 booster(s).
  • RJ22 connector J3 for direct coupling of MERG CAN-CAB or CAN-GC5V2.
  • 1A Internal booster, also useable for connection to programming track (J5)
  • Front switch to select programming track or main drive.
  • Refresh stack of 32 slots.
  • Optional power button.
  • Mobile DCC support only. Use the CAN-GC2 for accessories.

Final Version

Final board is produced and tested and working 100% as expected


The schematics
Pc-board and parts positions
The bill of materials
Gerber files
N.B. Only complete ordered kits will be supported!

Connection cable for CAN-GCA system

Cable connections are explained on this page.

Connectors & LEDs

1 Connection to programming rail, max 1Amp output
2 Main/Programming track indicator On=Main track, Off=Programming track
3 Main/Programming switch Up is normal mode, down is programming mode
4 Booster output power indicator
5 Connection for ORD-3 booster(s)
6 CAN bus with 12 Volt power (output)
7 Connector for CANCAB
8 CAN bus with 12V power (input)
9 CAN bus activitly indicator
10 Power indicator
11 ICSP: Programmer and optional power button.

Power button

An optional power button can be added to the ICSP connector on pin 1 (RB7) and pin 5 (Ground).
Pin 1 is closest pin to resistors R1 and R8.
Firmware version 433 or higher is needed.
This button controls track power and reports this on the CAN BUS to inform Rocrail.


The current firmware does not need any configuration.
All Loco, Programming and Booster commands on the CAN BUS are processed by the CAN-GC3.
It is not possible to have multiple CAN-GC3's in one and the same CAN network segment.


The CAN-GC3, CANCMD, has a fixed CanID:


Avoid using this CanID in other CAN-GCA nodes.

Programming Track

The CAN-GC3 supports Page mode and Direct mode programming.
Normally Direct mode should be used for common decoders.
Check the Direct mode option before programming.

Programming power

The standard 12V, coming from CAN-GC1e , is used for programming track as well.
Allthough other programmers often also work with no more that 12V,
it seems that some decoders have a bit of a problem with that.
To solve it, a higher Voltage will be the solution.
For this reason, the VR1 regulator on CAN-GC1e can be swapped with a LM2576T-adj type.
Pot1 on CAN-GC1e is already there and in that case can be used for adjusting the output between 12,5V and 18,5V.
CAN-GC1e will be equipped with the mentioned regulator from this day on.

can-gc3-en.txt · Last modified: 2020/07/06 14:53 by phg