Encoding data in multiple formats

摘要

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for modulating card information between a card reader and a user device. One of the methods includes receiving, from a read head of the card reader, card information associated with a card. The card information is encoded in a first format to be sent to the user device at a first data rate. The card information is encoded in a second format to be sent to the user device at a second data rate lower than the first data rate. The card information is sent to the user device encoded in the first format and the second format.

主权项

1. A computer implemented method of communication between a card reader and a user device, comprising:
receiving, from a read head of the card reader coupled to the user device, card information on a payment card; encoding the card information in a fast format packet to be sent to the user device at a first data rate; encoding the card information in a slow format packet to be sent to the user device at a second data rate lower than the first data rate; modulating the fast format packet and the slow format packet together into a signal that includes at least a first portion that corresponds to the fast format packet and at least a second portion that corresponds to the slow format packet and sending the signal over a communication port of the user device; initiating, at the user device, a demodulation process on the first portion of the signal that corresponds to the fast format packet; determining that the demodulation process on the portion of the signal that corresponds to the fast format packet has failed; in response to determining that the demodulation process on the portion of the signal that corresponds to the fast format packet has failed, demodulating the portion of the signal that corresponds to the slow format packet; and decoding the card information from the demodulated slow format packet.