55Troubleshooting! DANGER• THE CONTROL PANEL CONTAINS HIGH VOLTAGE! LIVE VOLTAGE CAN KILL.• ALWAYS DISCONNECT ELECTRICAL POWER BEFORE SERVICING OR PERFORMING MAINTE-NANCE TO THE MACHINE.• INSTALLATION OF THIS KIT, INCLUDING TESTING AND TROUBLESHOOTING SHOULD BE PER-FORMED ONLY BY AN AUTHORIZED VALLEY DEALER.• ALWAYS REPLACE ANY GUARDS OR SHIELDS THAT ARE REMOVED FOR PERFORMING MAINTE-NANCE.Theory of Operation VRI-iSThe Smart Relay Board (SRB) is able to control up to 495 sprinklers individually on a mechanized irrigationsystem. Each sprinkler can be pulsed to provide variable rate water application. The ICON module is used asthe user interface to enter and modify the sprinkler map which would identify the percent on for each sprinkler.The SRB sends messages to the COMM module (ID=00) via RS232, which is then relayed to the other COMMand valve assemblies. Each sprinkler valve assembly pulses its output based upon the information receivedfrom the SRB.The SRB controls the entire sprinkler system. It communicates to each sprinkler through a 24VDC-COM moduleand many valve assemblies each connected to a sprinkler. A GPS antenna, installed at the end of the pivotsends $GPGAA messages to the COM module (ID=FB). The COM module puts the message into a buffer. TheSRB then requests this buffer in order to retrieve the GPS $GPGAA message. The SRB then determines theposition of the pivot and based on that position, sprinkler parameters are updated to the valve assemblies basedon the VRI map.
