Portable field maintenance tool system having interchangeable functional modules

A portable handheld field maintenance tool for performing tasks on an equipment asset in a plant, the portable field maintenance tool comprising:

• a handheld base comprising:
• a first housing that is shaped and sized as a handheld unit, the first housing having in interior and an exterior;
• a computer processor carried within the interior of the first housing;
• an electronic display carried by the first housing to display information from the computer processor to the exterior of the first housing;
• a power source carried within the first housing that provides power to the computer processor and the electronic display;
• and
• a first set of electrical connectors carried by the first housing and operatively reachable from the exterior;
• a software module accessible by the computer processor, the software module configured to perform a predefined functional task relative to an equipment asset in a plant;
• and
• a functional module that is releasably mountable to the handheld base, the functional module comprising:
• a second housing having an exterior mating surface that is complementary to a portion of an exterior surface of the first housing so as to lockingly mate to the exterior surface of the first housing when the functional module is operatively mounted to the handheld base;
• a second set of electrical connectors carried by the second housing that operatively couple with the first set of electrical connectors when the functional module is operatively mounted to the handheld base;
• at least one interface connection carried by the second housing that operatively connects to the field device to perform at least one pre-defined functional task;
• and
• a computer control circuit that operatively connects to the computer processor to perform the predefined functional task when the functional module is operatively mounted to the handheld base;
• wherein, when the functional module is operatively mounted to the handheld base and the second the interface connection is operatively connected to the equipment asset, the functional module interacts with the software module to perform the pre-defined functional task.