The Dual Decoder system is designed to operate valves using a two-wire communication path. This system ensures efficient operation by detecting connected decoders and monitoring electrical current flow. When issues arise—such as low current readings, missing decoders, or communication errors—troubleshooting becomes essential to restore proper functionality.
The I-Core Dual system uses Dual decoders, which are exclusive to the I-Core controller. If the controller is replaced with a different model (such as ICC2, HCC, or ACC2), all Dual decoders must also be replaced. ICD decoders (ICD-100, ICD-200, & ICD-400) are compatible with the I-Core controller as well; however, when using an ICD-600, it must be programmed with the ICD-HP handheld programmer.
IMPORTANT: DUAL decoders do not require two-way communications, but duplicate station addresses should be avoided. DUAL decoders cannot be assigned to Pump, Master Valve, or Sensor outputs. Use the PMV/Sensor terminals on the I-Core controller to activate.
- Press the center button on the Dual module.
- Use the down arrow to select Read Current.
The display will show the current draw in milliamps (mA). In standby mode (no stations running), the total current should be approximately 3 mA per decoder connected to the controller.
The controller display shows “Fault”. This may be followed by a station number.
The Station Status light on the ICore System Status dashboard will also show a red LED when there has been a decoder fault.
Note: Fault light and message are only visible when stations are not running. During active irrigation, the Fault will not be visible. Station fault information may appear in the I-Core facepack as well as the Dual 48M Module. The I-Core will only show the last 5 faults in order.
If one or more station numbers are listed on the display, troubleshoot those stations. If there is no station number, troubleshoot the two-wire path connections.
Open the controller inner door to see additional diagnostic information on the DUAL48M display. The display may show Line Open or Line Fault.
The message may alternate with other screens. Allow a few seconds to see all displays.
- Press the Mode (center) button on the DUAL48M control panel. Select “Diagnostics” with the ▲▼ arrows, and press Mode to select.
Press the Mode button to select “Read Current”. This will show the current draw in milliamps (mA). In standby (no stations running), the total should be approximately 3-4mA multiplied by the number of decoders in the system. The number of decoders on the two-wire paths determines the correct current for the system.
When a station is turned on, the milliamps should increase by approximately 40mA, per solenoid attached to the active station.
- If a station is turned on, and the milliamps don’t increase enough, the controller will show a Station Fault followed by the station number.
- If a station is turned on, and the milliamps increase by more than the controller will allow, the controller will show a Station Fault followed by the station number.
- If the milliamps increase too much when no stations are supposed to be running, the controller will show a Fault with no station number and the DUAL48M will show Line Fault.
- Observe the current draw with no stations running. Divide the current draw by the number of decoder modules connected to the controller. It should be approximately 3-4 mA per decoder.
- Do not include DUAL-S surge suppression devices in current draw calculations- they do not increase the current.
- If no problem is observed with the current draw reading in standby (no stations running), turn on a station listed in the Fault message with the Manual Single Station feature, or a wireless remote control.
- Observe the Current Draw display. The current should increase by approximately 40 milliamps per solenoid connected to the decoder. Wait at least 30 seconds for the controller to complete its retry attempts and for the current to stabilize.
If the DUAL48M displays “Line Fault” when no stations are running, the most likely cause is a direct short between the two wires on the two-wire path (red and blue), resulting in excessive current over 500 mA.
If the Line Fault message appears only when a station is turned on, the issue is most likely a short in the decoder-to-solenoid wiring for the affected station(s).
| ICore Display | DUAL48M display in Standby | Cause | Corrective Action |
|---|---|---|---|
| Fault, no station | Line Open: Current draw too low on standby | Two-wire path disconnected | Check connections to two wire path |
| Line Fault: Current draw too high on standby | Short in two-wire path Too many decoders (more than 48) in two-wire path | Check two-wire path (red and blue must not touch) Verify number of decoders in two-wire path | |
| Fault with station numbers | DUAL48M display with Active Station | Cause | Corrective Action |
| Current Draw for station too low (station number will blink slowly) * | Decoder not programmed Decoder missing, damaged, or disconnected Solenoid missing, damaged, or disconnected | Program decoder address Repair/replace decoder or connections Repair or replace solenoid or decoder-to-solenoid wiring | |
| Current Draw for station too high (Line Fault will appear when station is running) | Shorted solenoid or solenoid wiring Multiple decoders with same address Too many solenoids connected | Repair/replace solenoid or decoder-to-solenoid wiring Remove duplicate addresses Remove excess solenoids |
The Dual module is not detecting the I-Core facepack.
- Push the Slide Lock Bar to power off the controller.
- Remove both the Power Module and the Dual Module.
- Reinstall the modules securely.
If the issue persists, one of the modules (Power Module or Dual Module) may need replacement. It is not possible to determine which module is faulty without further testing.
When the controller detects low current, it will attempt to resend the command to the station up to three times.
- The DUAL48M display shows the station number while sending the command to the decoder.
- If the current does not increase, the station number disappears for a few seconds—indicating that the expected current draw did not occur.
- After 4–5 seconds, the station number reappears during the retry attempt.
- If low current persists, the number disappears again.
- After three unsuccessful attempts, the station number disappears permanently, and a Fault message appears on the I-Core facepack display.
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