Summary

In the event of multiple No Connects (2-wire decoder communication failure), where a multitude of device message are present over a large section of 2-wire, read what's below for added information and resolution steps. 

Problematic Splices

The splices on the decoder could be corroded, the result of water intrusion due to improper splice hardware or otherwise. The correct splice hardware is the 3M DBR/Y-6 connector, in the provided waterproof capsule. This is the only splice hardware that meets specifications, and is included with every decoder set. They CANNOT be reused, so ensure to bring a new set if you need to replace the splice.

Malfunctioning Decoder

The decoder may be faulty, which can be seen by looking for the LEDs on the top of the decoder. If none are present when the decoder is in operation or when running a test of that device from the controller, or the WeatherTRAK mobile application, take the decoder to the controller. Plug it directly into the controller without the 2-wire path, and verify if the decoder is the issue via test from the controller menu.

IMPORTANT: Tools Required

#2 Phillips screwdriver

Wire stripper

NEW 3M DBR/Y-6 connectors

Approved mA clamp meter such as: Armada Pro 95i, Tempo 360B

Not all mA clamp meters have the required resolution to find the mA load discrepancy on the wire path. Approved mA clamp meters have low pass filter settings that provide a stable mA reading while devices are communicating over the two-wire, microamp resolution and a true RMS measurement.

Check the Controller

• Step 1:  Press the ALERTS button once. You will be directed to the Alerts menu. 
  • If an ER (error) is present directly below the VL (valve) section, this indicates that there are 1 or more valve errors present on the system. 
  •  A _ (dash) this will indicate that no errors (ER) are present for that section. 

    • Note:

      We are only focused on VL, valve errors.

       

• Step 2: Press the → button until you reach View Valve Status or sub menu Alerts: 03.

• Step 3: Press the SELECT button to View valve Status.
  • An NC (No Connect) will be present directly below any station number and or a Master valve(s) listed at the end of the station numbers (M1, M2, M3, and M4 all represent master valve 1,2,3, or 4 this will depend on how may master valves are being used or not) indicating a solenoid is drawing less than 75 MA.

• Note: 

  You will see the word ALERT flash periodically on the lower right-hand side of the screen if any alert error conditions have been detected by the system. If this is not flashing this means that no alert has been registered by the system. This is just a way of reminding the user.

   

What is a No Connect in 7x? 

• Before you start- make sure that the stations Program is NOT configured to OFF mode. If a Program is configured to OFF mode, it will not run a valve test any station that have been assigned to that program. For examples, say that Program A is set to Off and you have stations 1-10 on program A, the controller sill know that Program A is set to Off and will not run a valve test on stations 1-10.

• No Connect (NC) 
  • This type of alert can happen when the current draw for the valve solenoid is below 75mA. 
     
• Some of the possible causes:
  
  • The number of Max Active Stations exceeds the number of station decoders physically 
    connected to the controller. 
    • (Press Setup, press the → button to menu Setup: 09 displayed on the upper left-hand corner of the screen, and adjust as needed with the + or - buttons to the total of max activate stations needed for your site)

• A leg of the 2-wire path on the 2-wire input of the PCB’s is partially disconnected
•  A clear 48 station key module is missing.
•  No field wire is connected to a specific station decoder output. 
• The field wire terminated in the station decoder output is not making proper contact. 
• The field wire is broken or there is a corroded or failed splice after the decoder output.
• Improperly installed wire connections. 
• A decoder is not properly programmed.
• A decoder has failed and will need to be replaced.
• The Mini chassis has failed and will need to be completely replaced. 
   

• Expected controller behavior with a No Connect?
  • The controller will continue to irrigate when a “No Connect” condition is detected, there are times that some solenoids draw less than 75 mA, in which case users will need these stations to continue to irrigate. 
  • This will now be displayed as NI (Not connected but will Irrigate) within the MANUAL TEST menu (see image below), within the Valve Test sub menu. This is regardless of the Runtime valve test (RTVT) setting found in the SETUP menu, on Setup: 11 screens. 

• Possible Fixes: 
  • Properly connect solenoid to decoder with approved waterproof connections.
  • Properly connect or replace failed decoder.
  • Properly program the station decoder. 
  • Reduce the number of Max Active stations in the SETUP menu. 
  • Re-insert or repair the ribbon cable and verify sufficient number of 2-wire clear 48 station key(s) are installed. 
  • Conduct an Ohms test on the solenoid. If Ohms value is higher than 60-70 Ohms, this will typically indicate open circuit or corroded wiring. OL or Infinity indicate a true Open, this indicates that a wise within the solenoid coil is broken or the solenoid coil is burned, replace the solenoid. 
  • Replace the mini chassis if it has failed.

• Clearing a No Connect (NC) Alert

1. Press the ALERTS button.  
2. Press → until the View Valve Status screen displays.
3. Press * to clear the alert.
4. Once cleared If RTVT is set to On, the controller will run a self-vale test 15 seconds later and will register a valve fault if one is detected.

Multiple No Connect errors on a controller using 7X firmware will be an indication of the following:

• A leg of the 2-wire path on the 2-wire input of the PCB’s is partially disconnected
•  A clear 48 station key module is missing.
•  No field wire is connected to a specific station decoder output. 
• The field wire terminated in the station decoder output is not making proper contact. 
• The field wire is broken or there is a corroded or failed splice after the decoder output.
• Improperly installed wire connections. 
• A decoder is not properly programmed.
• A decoder has failed and will need to be replaced.
• The Mini chassis has failed and will need to be completely replaced. 

Multiple No Connect errors on a controller using 8X firmware will be an indication of the following:

• Solenoids have failed.
• Solenoids are not properly connected.

Check the Two-Wire Path

Before starting, identify your wire path configuration. If the wire path is looped, disconnect the furthest loop from the controller. If the wire path is a star or straight run, proceed to step 1.

1. Confirm the expected mA draw for the wire path or section of wire path you are testing. This can be done by summing the mA draw of each two-wire device downstream of your measurement location. (Refer to Device mA Draw table and example below)

Note: If you do not know the number of devices downstream of your mA measurement location, trace your wire path from the measurement location to the end of the wire path, opening each valve box and accounting for all of the inbound wire pairs. You can then use the Device mA Draw table to get your expected mA draw.

(Two-wire device mA draw) (device quantity) = Expected mA draw

2. Confirm that the mA draw on the red and black wires match. With your milliamp clamp meter, clamp the red wire and record the mA value. Do the same for the black wire. 

Note: When measuring mA with your clamp meter, it is important to have the wire in the center of the clamp meter (Alignment markers may be present) and perpendicular to the meter.

3. Compare the expected mA draw to the actual mA draw measured with your clamp meter at your measurement location.  

Note: This should be done when system is idle. mA draw while the system is watering will be higher due to running solenoids.

4. Work your way from the controller down the wire path, or use the binary search method, using the clamp meter to determine where the problem is. Once problem is identified, replace splice(s) or two-wire device(s) as necessary. For mA measurements lower than expected, use the Device mA draw table to see how many devices could still be connected between the wire path problem and the controller. Target that location on your wire path first.

Note: As you work your way down the two-wire, the expected mA draw will change as the current measured is for downstream devices only. Please see Two-wire mA Draw Example at the bottom of the page. Branch 1 indicates a small mA leak at the end of the wire path, causing our actual reading to be ~1mA higher than our expected reading. 

What Our mA Measurement Means

For more information see Interpreting Current Readings.

Determining Number of Devices

 The easiest Way to verify how may stations are configured on your system is by performing the following steps: 

1. Press the SETUP button once.
2. Press and old both the * and SELECT button at the same time.

This is the message that will appear:

• The first value will indicate the number stations that this type of platform could be CONFIGURED to, as long as the required hardware is being used. 
• The second number is the total number of stations that the controller FOUND available. 
• The last number is the total number of Max ACTIVE stations have been set.

This would tell me that there is a possibility that this controller is using 12 decoders.

Device mA Draw

*Measured with the Armada Pro 95i

Two-wire mA Draw Example