The HMI device encapsulates the functionality of the HMI layer of the architecture, including the HMI elements needed to:

• read sensor values;
• simulate manual loading of pegs and rings to the chain conveyor;
• write actuator values; and
• maintain resettable counts of "lost" (unassembled) rings and pegs and of peg/ring assemblies produced.

The MODEL device contains eight instances of the EMB_RES type, which in turn contain the Model elements for the corresponding Views, as well as logic to simulate the physics of the interactions among Model elements including their sensors and actuators and transfer of workpieces.

The CLOCK resource contains the simulation clock, whose events are distributed using the local multicast pattern. It also contains additional logic to provide "artificial gravity", i.e., a constant ON signal to the "motors" of the chutes in the PEG_CHUTE and RING_CHUTES resources.

The CHAIN_MDL resource contains an instance of the CNV_MDLL type, corresponding to the chain in the CHAIN view.

The SORT_MDL resource contains an instance of the SOL_MDLL type, corresponding to the sorter solenoid in the CHAIN view.

The PEG_CHUTE resource contains an instance of the CNV_MDLL type, corresponding to the CHUTE element of the CHUTES view.

The RING_CHUTES resource contains instances of the CNV_MDLL type, corresponding to the CHUTE element of the CHUTES view.

The BELT_MDL resource contains intances of the CNV_MDLL and CNVG_MDLL types, corresponding to the ASSY_CHUTE and RING_FEED elements of the CHUTES view, respectively.

The ASSY_MDL resource models the peg/ring assembly.

The INSP_MDL resource uses an instance of the WP_SENSE type to model the operation of the inspection station.

Inter- and intra-layer communication is implemented with the local multicast pattern, in particular for the distribution of the simulation clock and the simulation of workpiece transfer with instances of the LOADL and LOADLE types. The FBDK uses the Tagged Data design pattern to ensure consistency of the communicated events and data, as shown in the table below.

Where applicable, this table lists the correspondences between the tag names and the testbed's Sensor/Actuator labels, which are also used in the HMI.