BNC 645 - Manual (Page 31)

31
Notes
• If the Sync connector is disabled, the output signal is at a logic
“low” level.
• The Sync setting is stored in non-volatile memory, so it does not
change after power-off or a remote reset command is issued.
• For Sine, ramp and pulse waveforms, the Sync signal is a square
waveform with a 50% duty cycle. The Sync signal is a TTL “high”
when the waveform output is positive, relative to zero volts
(discard the dc offset setting). The Sync signal is a TTL “low” when
the waveform output is negative, relative to zero volts (discard
the dc offset setting).
• For Square waveforms, the Sync signal is a square waveform with
the same duty cycle.
• For arbitrary waveforms, the Sync signal is a square waveform
with a 50% duty cycle. The Sync signal is a TTL “high” when the
first waveform point is outputted.
• For internal-modulated AM, FM, PM, and PWM, the Sync signal is
aligned with the modulating waveform and is a square wave with
a 50% duty cycle. The Sync signal is a TTL “high” during the first
half of the modulating waveform.
• For external-modulated AM, FM, PM, and PWM, the Sync signal is
aligned with the carrier waveform and is a square wave with a
50% duty cycle.
• For FSK, the Sync signal is aligned with shifts in frequency. The
Sync signal is a TTL “high” during the output of the “hop”
frequency and “low” during that of the “carrier” frequency.
• For frequency sweeps with Marker Off, the Sync signal is a square
wave with a 50% duty cycle. The Sync signal is a TTL “high” in the
first half of the sweep and “low” in the second half. The frequency
of the sync signal is equal to the reciprocal of the sweep time. If
the Marker is enabled, the Sync signal setting will be ignored and
the Sync signal is a TTL “high” at the beginning of the sweep and
transitions to “low” at the marker frequency.
• For a triggered burst, the Sync signal becomes a TTL “high” when
the burst is triggered. The Sync signal transitions to a TTL “low” at
the end of the specified number of cycles (may not be the