To attain control and monitor capable of absorbing differences among the formats of communication messages to be outputted to different sorts of controllers.

A controller command generating/monitoring device 2 connected to plural controllers 4 of different sorts through a network 1 is provided with a communication control part 21 for communicating with respective controllers 4 through the network 1, an application part 22 for interfacing with a message conversion part 23 by using a command for each sort of a controller 4 and a reference message format answered from the controller 4, a message conversion rule edition part 24 having a message conversion rule, and the message conversion part 23 for converting a reference command message to be outputted to controllers 4 into a command message inherent in each controller 4 and converting an inherent response message from each controller 4 into a reference message format by using the message conversion rule.