QX-870 Trigger, New Master and Input 1: schematic and operation

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The attached file will show a simplified schematic of the input circuit to the QX-870. This diagram will show the electrical connections of Trigger, New Master, and Input 1 on connectors A, B and T. The diagram also shows the Standard trigger sensors (99-000020-xx, 99-000017-xx) wired into the circuit. The intent of this diagram is to help you understand how to wire the inputs for your application. Pay special attention to the wiring of the trigger, Notice that the Input Common line is toggled to control the read cycle. This is necessary in order for the QX-870 to pass the signal to other readers through connectors A and B. When the circuit is wired in this fashion, the New Master pin and Input 1 can not be used. To use The New Master pin, or to use input 1, you must re-wire the trigger sensor so that Input common is tied to Power, and the NPN trigger signal feeds into the Trigger2 line. When wired in the fashion, the trigger signal will not feed to other readers through connectors A and B. Common problems when wired incorrectly: Using the New Master pin triggers the reader Two readers triggered by one sensor when the trigger lines are not connected (the input common line may be tied together to cause this). Trigger input does not work. New Master pin does not work. New Master pin operation is intermittent.