Patent ID: 7031260
Filing Date: 2006-04-18
Classification: H04L

Abstract:
1. A central management apparatus for managing devices connected to device management units by data communication with first and second device management units using different communication methods, the central management apparatus comprising: a memory for storing a first transmission time set for the first device management unit and a second transmission time set for the second device management unit; a first counting unit for counting elapsed time from the first transmission time when data have not been received from the first device management unit at the first transmission time; a second counting unit for counting the elapsed time from the second transmission time when data have not been received from the second device management unit at the second transmission time; a threshold setting unit for setting a first threshold value for the first device management unit and setting a second threshold value different from the first threshold value for the second device management unit; and a determining unit for determining a no reception condition when the elapsed time by the first counting unit exceeds the first threshold value or the elapsed time counted by the second counting unit exceeds the second threshold value.