NPN pulse Debug process FP-AS310A

Environment and Parameter Verification

1. Confirm the main unit is powered on properly.

2. Ensure the data displayed on the diagnostic screen matches the communication data.

3. Verify that the NPN output function is enabled and correctly defined (Parameter E02). If E02 is set to Paddlewheel Pulse or Pulse V2, confirm this matches the intended configuration.

4. Check the NPN default state: Normally Closed (NC) or Normally Open (NO) as defined by Parameter E01.

5. Ensure the wiring is correct, the external power supply is stable, all unused wires are insulated, and the environment is free of magnetic interference.

Receiver Hardware, Circuit, and Software Verification

1. Access Parameter F03 to set the number of pulses per second for testing. At the receiving end, check whether the corresponding pulses are received and if the pulse count is accurate.

2. Confirm Parameter E03 (Pulse Width) is greater than or equal to the minimum pulse duration required by the receiving device.

3. Check that Parameter E14 (Pulse Unit) value and unit match the input requirements of the receiving program. Refer to the parameter table for detailed configuration.

4. Use Parameter F04 to test the receiving end. In the configuration screen:

   • Setting to open will disable conduction

   • Setting to conduct will enable conduction

5. Use a multimeter in current mode, connected between NPN+ and the power supply’s positive terminal, to check if current flows when C0 = 1. Alternatively, use the voltage mode to measure between NPN+ and NPN- and verify whether a voltage drop close to the power supply voltage appears when S0 = 1. If no proper output is observed on the first test, double-check the power circuit.

Results and Actions

1. If the NPN output is functioning, and the receiving device and software are also operating correctly, but data remains abnormal, check for other potential causes such as incorrect pipe size or paddlewheel malfunction.

2. The main unit may be damaged. If another unit is available, conduct a cross-test to verify the receiver, data processing program, and wiring.

3. Record the serial number of the unit, wiring diagram (including all flow meter-related connections), and the model/brand of the receiving device, and contact the manufacturer for support.

4. Confirm whether the receiving device, processing software, or wiring may be at fault.

Users should always refer to actual on-site conditions. For detailed troubleshooting and support, please contact LORRIC directly for further assistance.