50
Waveform Hold in Arbitrary Mode
Arbitrary waveforms can be paused and restarted on any channel by using the front panel MAN
HOLD key or a signal applied to the rear panel HOLD IN socket.
On multi
−
channel instruments the channels which are to be held by the MAN HOLD key or HOLD
IN socket must first be enabled using the
ARB HOLD INPUT
screen, accessed by pressing
the HOLD key.
ARB HOLD INPUT:
status: no hold
mode: disabled
Each channel is selected in turn using the channel SETUP keys and set using the
mode
soft
−
key; the mode changes between
disabled
and
enabled
with alternate key presses.
Pressing the front panel MAN HOLD key stops the waveform at the current level on all enabled
channels; pressing MAN HOLD a second time restarts the waveform from that level. If the
ARB HOLD INPUT
screen is currently selected the
status
field will change from
no hold
to
manual hold
while the waveform is paused.
A logic low or switch closure at the rear panel HOLD IN socket also stops the waveform at the
current level on all enabled channels; a logic high or switch opening restarts the waveform from
that level. If the
ARB HOLD INPUT
screen is currently selected the
status
field will
change from
no hold
to
ext. hold
while the waveform is paused.
If, while the waveform is held by either of the above means, the MAN TRIG key is pressed the
waveform is reset to its first point; the waveform will restart from this point when MAN HOLD is
pressed again or a high is applied to the rear panel HOLD IN socket.
Output Filter Setting
The output filter type is automatically chosen by the software to give the best signal quality for
the selected waveform. The choice can, however, be overridden by the user and this is most
probably a requirement with arbitrary waveforms.
To change the filter, press the FILTER key to call the
FILTER SETUP
screen.
FILTER SETUP
◊
mode: auto
type:
10MHz
eliptic
The default
mode
is
auto
which means that the software selects the most appropriate filter.
With the setting on
auto
the
type
can be changed manually but the choice will revert to the
automatic selection as soon as any relevant parameter is changed. To override the automatic
choice press the
mode
soft
−
key to select
manual
.
The four filter choices, which are either automatically selected or set manually with the
type
soft
−
key, are as follows:
•
10MHz elliptic:
The automatic choice up to 10MHz for sine, cosine, haversine,
havercosine, sinx/x and triangle. Would be the better choice for arb
waveforms with an essentially sinusoidal content.
•
16MHz elliptic:
The automatic choice above 10MHz for sine, cosine, haversine and
havercosine. Not recommended for any other waveforms.
•
10MHz Bessel:
The automatic choice for positive and negative ramps, arb and sequence.
•
No filter:
The automatic choice for squareware, pulse and pulse
−
trains. May be the
better choice for arb waveforms with an essentially rectangular content.
