| 摘要 |
A portable communication device communicates with a circuit breaker trip unit in a cost-efficient, power-effective manner. The portable communication device includes a keypad (10, 12), a display (78), an interface circuit (16) which couples data sent from the trip unit with the portable communication device, a microcomputer (13) which responds to the keypad (10, 12) and to the data sent from the trip unit for controlling the display (78), a local power source which provides power to the portable communication device, and a power switch which is responsive to the microcomputer for disabling the local power source during periods when data is not being received from the trip unit. The microcomputer may be arranged to directly control the power switch. In this manner the microcomputer can command the power switch to disable the local power when the absence of data from the trip unit indicates that power to the portable communication device is not needed. |
