L
R
OGIC
AIL
TECHNOLOGIES
21175 Tomball Pkwy
Suite 287
Houston, TX 77070
Getting started
Thank you for purchasing a Logic Rail Technologies product! Please familiarize yourself with all the instructions prior to
installing this board. The Grade Crossing Pro/2 Expander (versions GCP/2-EXP, GCP/2-EXP-IR, and GCP/2-EXP-X) is
used in conjunction with the Grade Crossing Pro/2 for prototypical operation of a multitrack grade crossing. Four sensors
(photocells or infrared emitters and detectors) are used for bidirectional train detection. External detectors (available from
other suppliers) can also be used. The layout of the sensors is illustrated below. You MUST install the sensors in the exact
order (WF-WN-EN-EF) shown! The WF and EF sensors may be located as far away from the crossing as you would like. If
you are installing gates then putting these farther out will give the gates enough time to lower before the train reaches the
crossing. An HO scale train running a scale 40 MPH would cover 12 inches in about 1.5 seconds. You will likely choose to
have your gates lower in approximately 4 seconds. So, that would suggest that you should locate WF and EF around 36
inches from the crossing; consider more distance if you're running faster trains or less distance if you're running slower
trains! If you are NOT installing gates then you can choose to place WF and EF wherever convenient and whatever amount
of advance notice you want to give your scale motorists before the train reaches the crossing!
Sensor
WF
You should make all the connections to the Grade Crossing Pro/2 Expander before connecting it to the Grade Crossing
Pro/2. You should mount the Grade Crossing Pro/2 Expander as close as possible to the Grade Crossing Pro/2 keeping in
mind the short length of the interconnecting cable (included). Use the four mounting holes provided which will accept #4
screws; do not enlarge the holes as damage to the circuit board can result and your warranty will be voided!
The Grade Crossing Pro/2 Expander board has a set of 7 configuration switches on it. Each switch is briefly described
below with more details later in these instructions. Note that 4 of the switches MUST match the exact settings of those same
switches on the Grade Crossing Pro/2 board! Full descriptions of those switches can be found in the Grade Crossing Pro/2
instructions. The ON/CLOSED position is towards the edge of the board.
Switch Name
SETUP
GCP/2 Expander is in normal operating mode
SEN TYPE
Sensors are photocells or external current
SEN POL
GATES USED
GATE DELAY
BELL MODE
BELL SHUTOFF
Powering the board
The Grade Crossing Pro/2 Expander receives DC power from the Grade Crossing Pro/2 through the expansion cable
provided with this product. Page 6 shows you how to connect this cable. Power consumption ranges from ~50 mA (photocell
version) to ~185 mA (infrared version).
TM
"Sophisticated
Model Railroad
Electronics"
Phone: (281) 251-5813
email: info@logicrailtech.com
http://www.logicrailtech.com
Sensor
W
WN
Meaning when OFF/OPEN
detectors
See text in the Sensor Modes section
MUST MATCH THE GCP/2 SETTING!
MUST MATCH THE GCP/2 SETTING!
MUST MATCH THE GCP/2 SETTING!
MUST MATCH THE GCP/2 SETTING!
Grade Crossing Pro/2 Expander
Instructions
(covers versions GCP/2-EXP, GCP/2-EXP-IR, and
GCP/2-EXP-X)
Sensor
E
EN
Meaning when ON/CLOSED
GCP/2 Expander is in sensor setup mode
Sensors are infrared
See text in the Sensor Modes section
Revised 4/15/2024
Sensor
EF
1
Need help?
Do you have a question about the Grade Crossing Pro/2 Expander and is the answer not in the manual?
Questions and answers