The Signaling Solution, Inc.
PO Box 25
West Terre Haute,
IN 47885
Phone:(812) 533-1345
Fax:(708) 570-6140

GCX Installation Procedure
Tools Required
  • A small soldering iron, no more than 40 watts. A 25-watt iron would be ideal
  • A small jeweler’s screwdriver


The Figure below shows how the GCX and related items will look when ready for installation. Note the hardware components. The major items are identified individually

GCX Assembly and Parts
GCX Assebly and Parts
Item 2: Board Activity indicator, LED
Item 5: Card edge connector
Item 6:
Stainless steel #4 hex nut (2)
Item 7:
Stainless steel #4 tooth lock washer (2)
Item 8
: Stainless steel #4 flat washer (4)
Item 9:
Pan-head # 4-40 Stainless steel machine screws (2)
Item 11:
Angle brackets (2)
Note: The board activity indicator is a LED which blinks about 2 times per second whenever power is applied to the GCX. If the LED is out completely, the power supply is either not connected, or the 5-volt supply on the board is shorted to ground by a connection to pin 16. If it is on, but not flashing, then the processor is not functioning. Turn off the power to the board by unplugging the AC adapter provided for about 10 seconds. Then plug it back in. If the LED still does not blink, the board may not be working.

Physical Installation of the GCX Board:

The first and foremost step is to decide upon a location to mount the GCX board.

Suggestion: We suggest that you mount your first GCX on the same mounting board as the GCC, and just to its right. Each additional GCX should be mounted just to the right of the previous one. This plan will simplify the wiring from each additional board to the previous one. Since each of these boards, with its mounting connector, is about 4 inches wide, a plywood panel 10” high or piece of 1” x 10” that’s 4” long for each of the boards you need to mount will work just fine. You can do much of the wiring while this panel is on your workbench. Then install the board near the grade crossing beneath the layout and connect the wires to the track, cross-bucks, and motor drives.

GCX Board Installation
GCX Pin Diagram
  • Make sure that there is adequate light and room to work. Try to make it as convenient as possible.
  • The Card Edge Connector Pin Diagram is provided showing all of the pins, and identifying them for your convenience. Note that the top row of pins is numbered from 1 to 18. The bottom row is lettered as follows: A, B, C, D, E, F, H, J, K, L, M, N, P, R, S, T, U, and V.
  • Mounting hardware is provided with the GCX to give you all you need to install the board as described in Figure 3-2 GCX Board Installation.
  • Figure 3-2 shows an optional barrier strip used to strain relief the four wires required to connect the GCX to the train running circuits. If the length of these wires is fairly short, less than about 5 or 6 feet, and your trains don’t draw much current, less than an amp or so, you can probably wire the track circuits using 20 or 22 gauge wire. Make sure you install a strain relief of some kind near where the barrier strip is shown.

    Note: The connector pins can handle such wires. This simple precaution will prevent damage to the connector if someone accidentally pulls on the wires. In fact, it is always good practice to provide a strain relief for wiring going to connectors. The strain reliefs are very cheap; connectors are very expensive and time-consuming to replace. Most wiring to train tracks will be heavier and longer. Because the pins on the connector are limited to 20-gauge wire, you will need a convenient place to convert from the heavy track wires to short, small gauge wires that go to the connector. A barrier strip like this is a good, professional way to do it. A four-circuit barrier strip is available from many sources. One good example would be a product by Cinch-Jones called the model 4-140 Barrier Strip. It’s available from Digikey (1-800-344-4539) for less than $2.00. You may not need this, or you may have other methods you prefer, but you are limited to 20-gauge wires to the connector.
For more details please check the GCX Owner's Manual.
The Signaling Solution, Inc. PO Box 25, West Terre Haute, IN 47885