Register the card before use if DENY is shown.
Please make sure no interference from other reader nearby and do not use more than one card at the same time.
Please make sure both reader and cards use are at the same format. Contact us if format of the card is different with the reader.
Any metal material around or in the back of the proximity unit will affect its proximity quality. Please remove any metal or foil material from the card or the reader to prevent interference between the card and the reader.
Please contact us for further testing if card is still unable to use with the reader when all of the above issues are ruled out.