Symmetricom 5071A, Operating And Programming Manual

Page: 38 / 194

Chapter 1 Getting Started
Performing Basic Tasks
10 Operating and Programming Manual
Performing Basic Tasks
Things You May Do at Any Time During These Basic Tasks
1. During the following tasks, you may, at any time, return to the Top menu by
pressing the Top key.
2. At any time, you may cancel a pending operation or data entry task by pressing
Prev .
3. If you need to adjust the display for better readability, hold down Shift , then press
Inc or Dec .
Synchronizing to an External 1 PPS Reference
The 5071A requires a sync pulse with these characteristics:
• +2 to +10 Volts into 50Ω (TTL Threshold),
• Width = 100 ns minimum to 100 µs maximum, Rise time <50 ns.
The 1PPS output from a 5061A/B or 5071A meets these sync-pulse requirements. As
an alternative, the 1pps may be manually synchronized (see page 18).
Synchronize the 5071A‘s 1pps Outputs (to the reference source) with the following
procedure:
1 Connect a 1pps sync-pulse from the reference clock to the instrument's front (or rear)
sync-input.
2 Press Top , then

once to select the CLOCK option.
3 Press Enter .
SET option of the CLOCK menu is selected.
4 Press

three times.
SYNC option (CLOCK menu) is selected.
5 Press Enter , then

to select ARM FRONT or ARM REAR.
6 Press Enter to arm the selected sync input connection. The 5071A will synchronize
to within ± 50 ns on the next sync pulse and the display will show Caught a sync
pulse. (See Notes on the following page.)
NOTE