User Manual 74
10.1 Sync
The sync signal is output from the
[Sync]
connector at the front panel. The instrument could
output the sync signals of basic waveforms (except Noise), arbitrary waveforms (except DC),
Harmonics, Sweep signal, Burst signal and modulated signal from a single channel or two
channels at the same time.
The
Sync
signal is a square wave that is "high" in the first half of the cycle and "low" in the
second half. When sync signal is disabled, the output level at the
[Sync]
connector is logic
low.
The amplitude of Sync signal is not adjustable and fixed at TTL level.
Sync Signals of Various Waveforms
For Sine, Square, Ramp and Pulse, the sync signal is a Square with 50% duty cycle. It is TTL
high level relative to 0V (or DC offset) when the output is positive and TTL low level relative to
0V (or DC offset) when the output is negative.
For arbitrary waveform, the sync signal is a square with variable duty cycle. The sync signal
is TTL high level when the amplitude of the output waveform reaches certain value.
For harmonics, sync signal is a square with variable duty cycle and takes the harmonic order
as reference.
For AM, DSB-AM, FM, PM and PWM, in internal modulation mode, the sync signal is a
Square with 50% duty cycle and takes modulating frequency as reference. It is TTL high level
in the first half period of the modulation waveform. In external modulation mode, there is no
sync signal output.
For 2ASK, 2FSK, 2PSK, BPSK, QPSK, 3FSK, 4FSK and OSK, in internal modulation mode,
the sync signal takes their Rate as reference and is a Square with 50% duty cycle. For 2ASK,
2FSK, 2PSK and OSK, in external modulation mode, there is no sync signal output.
For Sweep, the sync signal changes from low-level to high-level at the specified mark
frequency point or greater than the mark frequency.
For a N cycle burst, in internal and manual trigger mode, the sync signal is TTL high level
when burst starts and transforms to TTL low level while the specified number of cycles end (if
the waveform has a relative start phase, the crossing point may not be zero). For an infinite
burst, in manual trigger mode, its sync signal is the same as the sync signal of a continuous
waveform. For all burst type, in external trigger mode, there is no sync signal output.
