Introduction Your PM6685 Counter is designed to bring you a new dimension to portable and bench-top counting. It offers significantly increased performance compared to traditional counters. The Counter offers the following advantages: - Ten digits of frequency resolution per second and 250 ps resolution, as a result of high-resolution interpolating reciprocal counting - A 2.7 GHz input frequency option - A foolproof auto trigger function New powerful and versatile functions The unique versatile auto sensitivity and auto waveform compensation takes care of all triggering from 50 Hz and up. It even optimizes itself to the requirements of different measuring functions. Another unique feature in your instrument is the bar-graph level monitor. It always shows you the input signal level on a dB scale to verify proper signal strength. The burst frequency and PRF functions measure bursts and AM signals without any external synchronization signal. To solve even tougher tasks, the counter has complete arming possibilities which lets you synchronize measurements with external events. You can even delay the arming of the counter (compare to delayed time base triggering in an oscilloscope). Read more about Arming in Chapter 7, "Measurement Control”. No mistakes You will soon find that your new Counter is a delight to operate. One example is the back light LCD that shows you measurement results, setting status, and operator messages. The AUTO function triggers automatically on any input wave form. A bus-ieam mode simplifies GPIB programming. With bus-leam mode, manual counter settings can be transferred to the controller for later reprogramming, There is no need to learn code and syntax for each individual counter setting if you are an occasional bus user.