PURPOSE: To provide a tracking device which can enhance the consistency of the position of a substance and tracking information when a substance carrying system starts after it has stopped by providing a restarting value correction means which corrects tracking position information by a tracking means by the difference between a read-out count value and a present count value.
CONSTITUTION: When no change has been made in the position of a substance during the period of time from the time when a carrying line was suspended to the time when the line is restarted, tracking information is corrected by a restarting value correction means 24 by the difference B1-B2 between a count value B1 read out of a non-volatile memory 27 and a present count value B2 by a pre-set counter 18, tracking information thereby becomes substantially continuous to information at the time when a carrying line was suspended. Therefore, even if the pre-set value or the count value of the pre-set counter 18 is different from that when the line is suspended during the period of time from the time when the line was suspended to the time when the line is restarted, events take place in a form substantially continuous to the time when the carrying line was suspended, besides, tracking information with the position of a substance can thereby take place.
FUCHINAMI TOSHIAKI
AGO YASUTO
