Station Decoder Installation
The station decoder module is available in 1-station, 2-station, or 4-station configuration.
The stand-alone GDC model can handle up to 100 stations per output board. These stations can be connected to the output
board terminals in any configuration (25 stations connected to each of the four terminal pairs or 100 stations connected to one
terminal pair, etc.). The decoder modules can be connected in parallel anywhere on the two-wire communication line connected
to the station terminals. Each station can activate up to two solenoids.
When a Tri-Comm Cellular modem is installed in the 2nd output board position, the maximum number of stations on the
1st output board is increased up to 200 stations.
It is recommended that the decoder modules are installed in an approved valve box to provide easy access to the wiring.
Use 3M DBR/Y to waterproof all connectors.
Recommended Controller-to-Decoder cable: 14 AWG (2.5mm
2
), solid copper, jacketed 2-conductor, direct burial.
The preferred wire make and model is the Paige Irrigation Wire, Spec P7350D.
Recommended Decoder-to-Solenoid cable: 14 AWG (2.5mm
2
), solid copper, 2-conductor, direct burial. The preferred wire
make and model is the Paige Irrigation Wire, Spec P7351D.
Burial Depth
Toro recommends that the Controller-to-Decoder and Decoder-to-Solenoid cables should have a minimum cover of 6"
(150mm). The irrigation plan may specify additional depth to be consistent with the depth of mainline or lateral pipe work and/
or soil conditioning procedures such as aeration. Installation procedures must comply with all applicable local and national
electrical codes.
• Use only wire approved for direct burial if installing the wires underground without conduit.
• All field wiring splices must be accessible to facilitate troubleshooting and/or service.
Step 1 – Route communication cable from the controller to the station decoder module installation location.
The maximum wire length between the controller and the decoder module is 15,000' (4500m).
Step 2 – Secure the communication wires to terminal 1 of the GDC output board. White wire onto the 1st terminal and black
wire onto the second terminal. See Figure 4.
Step 3 – Install the decoder module in a valve box. Record the decoder module’s address number found on the side label.
This address number identifies the station(s) that the decoder module control.
Step 4 – Secure the communication wires to the decoder module’s black and white wires. Connect the black communication
wire to the black decoder module wire. Connect the remaining communication wire (red or white) to the white
decoder module wire. Use 3M DBR/Y to properly water-proof all wire connections.
Step 5 – Route output wires from the decoder module to the solenoid.
The maximum wire length between the decoder module and the solenoid is 410' (125m).
Step 6 – Connect the solenoid wires to the decoder module’s station wires. The station wires are color coded for easy
identification. Connect the solid colored (red, green, orange or blue) station wire to the red/white solenoid wire.
Connect the similar color station wire with black stripe to the black solenoid wire. Use 3M DBR/Y to properly water-
proof all wire connections.
Step 7 – Connect an additional solenoid to the station wire as necessary.
Each station has a maximum load of two solenoids.
Step 8 – Repeat Steps 3–8 for additional decoder modules.
