To prevent non-SI unit from being displayed on a display part of a host in process control using a field bus standardized by Fieldbus Foundation.

A non-SI unit detection deletion part 105 detects the industrial unit codes of non-SI units from among device specifications acquired by a field equipment data acquisition part 104 by using a non-SI unit definition dictionary file 103. A non-SI unit detection deletion part 105 deletes the industrial unit codes of non-SI units detected from among the device specifications. An acquisition data conversion part 106 converts the described industrial units into a display character string in the device specifications with no non-SI unit industrial unit code.