The APMC-406A is a monitor for 3-phase power lines that supports variable frequency power monitoring. It measures parameters associated with 3-phase power lines as follows:

• 13 steady state and 3 transient parameters for measurement of aircraft electrical power characteristics
• active, apparent power and their ratio

The APMC-406A has a programmable gain amplifier, an analog-to-digital converter and a 65,536-point conversion table for each of the six channels. All six channels are sampled simultaneously at 2 Msps.

The algorithm waits for a positive-going-zero crossing on a channel for periodic calculations and resets the accumulators for the various parameters. The algorithm ends on either a subsequent half or full period zero-crossing that results in a parameter transmission or further accumulation for one second duration parameters. The processing algorithm is a hard-wired state machine with no micro-code or forbidden states.