RIGOL DG4000 Series - Manual (Page 175)

Chapter 10 Utility and System Settings RIGOL
DG4000 Series User’s Guide 10-3
Channel Setting
This section takes CH1 for example to illustrate how to set the channel. The setting
method for CH2 is quite the same.
Sync
DG4000 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
output from the [Sync] connector at the front panel.
1. Sync On/Off
Enable or disable sync signal at the [Sync] connector. Press Utility 
CH1Set  Sync to select “On” or “Off” for the sync signal output. The
default is “On”, namely transmitting the sync signal to the [Sync] connector.
If sync signal is disabled, the output level at the [Sync] connector is logic low.
2. 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, 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 ASK, FSK, PSK, BPSK, QPSK, 3FSK and 4FSK, the sync signal takes
ASK/FSK/PSK/BPSK/QPSK/3FSK/4FSK Rate as reference and is a Square