| 摘要 |
PROBLEM TO BE SOLVED: To conduct periodic transmission by a protocol necessary for the change of transaction at the time of a low power consumption mode of stopping power supply to a main control unit. SOLUTION: A PE 24 creates DHCP REQUEST voluntarily by an IC packet creating unit 247 at a time interval set to a Timer (1) of a periodical transmitting interval time setting unit 249 by the control of a network transmission control unit 241 even in an energy-saving mode that a CPU does not operate, and conducts periodic transmission. Alternatively, the periodic transmission of a DHCP REQUEST packet is continuously conducted while there is the reception of DHCP ACK responding to a request, and holds communication conditions. However, in the case that there is no response within a time set to a Timer (2) to the DHCP REQUEST packet, the periodic transmission is interrupted, and this packet is retransmitted by a retransmission control unit 2411. COPYRIGHT: (C)2009,JPO&INPIT |
