The HPM Communication and Control Processor (51403988-150) performs the network communication functions of the HPM, including network data access and time-stamping. 51403988-150 Control Processor executes regulatory, logic, and sequence functions, and user programming. The Universal Control Network (UCN) is a high-speed, high-security process control network. It features a 5-megabit/second, carrier band with token bus access control.

The HPMM card set consists of following assemblies:

• High-Performance Comm/Control card Replaces 51403422-150
• High-Performance I/O Link card (51309276-150)
• HPM UCN Interface module ((51402573-150)

The HPMM assemblies occupy the two left-most slot positions in the card file. The HPM UCN Interface module mounts in the connector beneath the High-Performance Comm/Control card in the first slot. High-Performance I/O Link Card (51309276-150) consists of an I/O Link processor, SRAM through which the processor communicates with the Communications/Control card, an I/O Link driver/receiver interface, and a +24 Vdc to +5 Vdc power converter that provides +5 Vdc for both HPMM cards and the HPM UCN Interface module.

When power is applied to the HPMM, the Power indicator on each HPMM card and the HPM UCN Interface module lights. The Power indicator is illuminated whenever 24 Vdc from the cabinet Power System is present.

The Status indicator on the High-Performance Communications/Control card illuminates momentarily after applying power. Internal test routines are executed upon applying power, and the Status indicator remains on if the tests are successfully completed. The steady illumination of the Status indicator signifies that no test failures were detected.

The UCN cable in use indicators are visible at the front of the HPM UCN Interface module (Rx-A and Rx-B) as well as under the front cover of the High-Performance Comm/Control card (UCN A and UCN B).