Transmission delay in a serial bus connected network is determined by
transmitting a Ping packet which is replied to in a physical layer of the bus from
a request node to a response node, and measuring the time required from transmission
of Ping packet by the request node until a Self—ID packet corresponding
to the Ping packet is returned to the request node. The delay deviation between
cycle timers of the request node and the response node is compensated by this transmission
delay. The delay deviation may be also compensated using a time stamp.