GV FAE Knowledge

Article ID: GV4-19-02-23-Ch
Released Date: 02/23/2019

Applied to
GV-AS Controllers with Wiegand Interface

Symptom
GV-AS Controller may fail to respond to readers connected through its Wiegand interface, i.e. information received by the Wiegand reader wasn’t transmitted to the GV-AS Controller.

Troubleshooting
The abovementioned symptom may be due to insufficient voltage between the Wiegand interface of GV-AS Controller and the reader. Follow the steps below to commence troubleshooting.

1. Make sure the reader is properly connected to the Wiegand port of GV-AS Controller.
2. Use a voltage meter to measure the voltage between D0 and GND, as well as D1 and GND of the controller’s Wiegand port.
3. If one or both of the measurements are lower than DC 3 V, proceed to the Solution below, if not, please contact our support team (support@geovision.com.tw) for other possible causes for the issue.

Solution
To resolve the issue of insufficient voltage, follow the steps below.

1. Apply two resistors of 3.3 or 4.7 kΩ to the Wiegand port with insufficient voltage, one between D0 and 12 V, and one between D1 and 12 V, as illustrated.

   

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2. Repeat Step 2 in the Troubleshooting section above to make sure the voltage has now surpassed DC 3 V.
3. The GV-AS Controller shall now respond properly to the Wiegand reader.

IMPORTANT: Make sure the two resistors applied are insulated from one another.