Table of Contents
Advertisement
OPERATION
2 Output Blanking
Level-The
Z output blanking level can
be set to one of two levels: OV (LOW) or 5V (HIGH)
nominal
(also, a provision
is made on the I/O board for
15V nominal).
The purpose of the blanking pulse will de-
pend on whether the instrument
is in the CRT, plotter, or
oscilloscope
modes.
If the instrument
is programmed
for the CRT mode, the
blanking
level is intended
to blank the beam during
the
beam retrace period. If the instrument
is being used in the
plotter mode, the Z output blanking
level can be used to
tell the plotter to lift the pen and return to the home posi-
tion. In the oscilloscope mode, the Z output blanking pulse
can be used to triger
the oscilloscope to begin the horizon-
tal sweep cycle.
Program the Z output blanking
level as follows:
1. Press SHIFT, OTHER, 6. The unit will
display
the
presently programmed
blanking level (HIGH or LOW)
as in this example:
Z BLANK
= LOW
2. Use the Uprange
or Downrange
key to toggle the
display between LOW and HIGH
levels.
3. The blanking
level is placed into effect immediately.
4. Press CHANNEL
to return to previous
mode.
Discussion
Figure 3-13 demonstrates
the operation
of the blanking
pulse. In (A) a HIGH level is assumed, while (B) shows
a blanking
pulse with a LOW level. Note that one pulse
is essentially
the inverted form of the other.
During the transmission
of data through the XY outputs,
the Z output is at the non-blanking
level (OV when pro-
grammed for HIGH blanking,
5V when programmed
for
LOW blanking).
After each transmission
sequence, the Z
output assumes the programmed blanking level. Note that
the transmission
sequence is recurrent
in the CRT and
oscilloscope modes, but it occurs only once with each XY
trigger in the plotter mode.
BLANK BEAM CRT MODE,
PENUP ,PLOTTER MODE,
TRIGGER SCOPE ~OSCUOSCOPE
MODE,
_illii
f[NG
DATA TRANSMlSSlON
PLOTTER SEOUENCE r--
STARTS HERE
A. HlGH BLANKING
LEVEL
DATA TRANSMISSION
:r
:u-'ir
PREVIOUS BLANKING
BLANK BEAM ,CRT MODEl
PULSE
PENUP iPLOTTER MODE,
TRIGGER SCOPE
,OSClLLOSCOPE MODE,
B. LOW BLANKING
LEVEL
Figure 3-13. Output
Blanking
Levels
3-28
Advertisement
Table of Contents
