Wireless card reader system

A wireless card reader system comprising:

• a card reader terminal that is battery-driven and obtains card data stored in a card for verification;
• a high-order host apparatus that verifies the card data, changes an operating state of a target device when a verification result is successful, and sends the verification result;
• and
• an interface apparatus that relays communication between the card reader terminal and the high-order host apparatus,
• wherein:
• the card reader terminal is operable in a normal mode or in a sleep mode with a lower power consumption than a power consumption of the normal mode;
• the card reader terminal switches from the normal mode to the sleep mode after sending the card data to the interface apparatus in the normal mode;
• the card reader terminal temporarily returns from the sleep mode to the normal mode to perform polling, which is an operation to send an inquiry for the verification result to the interface apparatus, and obtains the verification result sent from the high-order host apparatus to the interface apparatus;
• a first time is a time at which the operating state of the target device is changed by the high-order host apparatus;
• a period before a state change is a period before the first time;
• a period after the state change is a period after the first time;
• and
• the polling is performed less frequently in the period before the state change than in the period after the state change.