3
Theory of Operation
42
Keysight N1911A/1912A Service Guide
PPMC Assembly
Purpose
– Provides the main processor and memory for the power meter
– Provides external interfaces for LAN and USB
– Stores the power meter firmware in flash EEPROM
– Stores the power meter serial number and option data
Inputs
– Power supplies [from PSU, via main board]
– Control and data lines [from main board, DAP(s), and front panel]
– LAN/ USB communications [from external equipment]
– GPIB communications [from external equipment, via main board]
Outputs
– Control, address, and data lines [to main board, DAP(s), and front panel]