Patent ID: 8321493

Claim:
A field device connected to a network, the field device comprising: a storage section; a communication section for performing communication via the network; and an arithmetic control section for controlling the field device entirely by executing a main task under an execution environment, and controlling an independent operation mechanism that starts a first and a second additional task independently of a device-unique function, where the device-unique function comprises the main task, the execution environment, and a hardware resource, wherein the independent process operation mechanism assigns a first .group identifier, a first unique address space and a first unique name space to the started first additional task, and assigns a second group identifier, a second unique address space and a second unique name space to the started second additional task, wherein the independent operation mechanism is configured to receive an operation request from the first additional task to the second additional task, wherein if the independent operation mechanism receives the operation request from the first additional task to the second additional task, and determines that the first group identifier and the second group identifier are the same, the independent operation mechanism transmits the operation request to the second additional task, and if the independent operation mechanism receives the operation request from the first additional task to the second additional task, and determines that the first group identifier and the second group identifier are not the same, the independent operation mechanism returns an error to the first additional task.