Return; Contrast Decrease; Contrast Increase; Local - Agilent Technologies E8257D PSG User Manual

Signal Generator Overview
Front Panel

25. Return

Pressing this hardkey displays the previous softkey menu. It enables you to step back through the
menus until you reach the first menu you selected.

26. Contrast Decrease

Pressing this hardkey causes the display background to darken.

27. Contrast Increase

Pressing this hardkey causes the display background to lighten.

28. Local

Pressing this hardkey deactivates remote operation and returns the signal generator to front–panel
control.

29. Preset

Pressing this hardkey sets the signal generator to a known state (factory or user–defined).

30. Line Power LED

This green LED indicates when the signal generator power switch is set to the on position.

31. LINE

In the on position, this switch activates full power to the signal generator; in standby, it deactivates
all signal generator functions. In standby, the signal generator remains connected to the line power
and power is supplied to some internal circuits.

32. Standby LED

This yellow LED indicates when the signal generator power switch is set to the standby condition.

33. SYMBOL SYNC

This female BNC input connector is CMOS–compatible and accepts an externally supplied symbol
sync signal for use with the internal baseband generator (Option 601/602). The expected input is a
3.3 V CMOS bit clock signal (which is also TTL compatible). SYMBOL SYNC might occur once per
symbol or be a single one–bit–wide pulse that is used to synchronize the first bit of the first symbol.
The maximum clock rate is 50 MHz. The damage levels are > +5.5 V and < −0.5V. The nominal input
impedance is not definable. SYMBOL SYNC can be used in two modes:
• When used as a symbol sync in conjunction with a data clock, the signal must be high during the
first data bit of the symbol. The signal must be valid during the falling edge of the data clock
signal and may be a single pulse or continuous.
• When the SYMBOL SYNC itself is used as the (symbol) clock, the CMOS falling edge is used to
clock the DATA signal.
14 Chapter 1