Compass Card - Implementation

Implementation

The following process takes place when a user "taps" their card on a reader:

• Authenticates the microchip's serial number (to avoid counterfeited or stolen cards)
• Reads the rider's balance and/or passes
• Reports the rider's activity to the Compass Card server
• Writes the new balance (if applicable)

The next behavior depends on the reader:

• Displays a Thank You message along with a small green light for on-platform readers such as the Coaster, Sprinter, and San Diego Trolley.
• Shows green light and beeps once if Compass Card has valid fare, or shows a red light with an error message and beeps three times if the card is not valid or a read error occurs, for readers installed next to fareboxes. For passes, the expiration date of the pass is also displayed when the green light is lit and the reader beeps once.
• Beeps once if the Compass card has valid fare, or beeps three times if the card is not valid or a read error occurs, for readers integrated into the farebox. For passes, the expiration date of the pass is also displayed shortly after the reader beeps once.
• The driver's side computer will also show OK for a successful pass read. A type of bird vocalization that sounds different from the standard confirmation beep will occur for Youth or Senior/Disabled/Medicare passes that are valid, and the driver's side computer will show YTH for the Youth pass or SDM for the Senior/Disabled/Medicare pass.

Read errors that are displayed on the reader screen can include, but are not limited to:

• Invalid CRC.
• Invalid Card, can occur the first time on some readers even with a valid card, but if the card is valid a second attempt will register correctly. (The driver's side computer will show as NV for an invalid card error).
• Operation Failed, if an add value was initiated from the farebox computer but did not work.
• Read Error. (Seems to occur only on some readers integrated into the farebox, and turning the card sideways when tapping may work around this problem).
• Feedback used too soon. (The driver's side computer will show as FBK for a feedback related error).
• Already Touched.