Tektronix VM700T User manual

User Manual
VM700T Video Measurement Set
Option 1G Echo and Rounding Errors
Measurements
070-9651-00
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - FAX [phone] - TestEquipmentDepot.com

VM700T Option 1G Echo and Rounding Errors Measurements User Manual i
Table of Contents
Preface iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Option
Configuring the Echo Rounding Limits Files 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . .
Create a Video Limit File for Echo Rounding 1–3. . . . . . . . . . . . . . . . . . . . . . .
Editing an Echo Rounding Limit Text Parameter 1–5. . . . . . . . . . . . . . . . . . . . .
Deleting a Modified Echo Rounding Limit File 1–5. . . . . . . . . . . . . . . . . . . . . .
Configuring the Video Source Files 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Editing the Video Source File 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the Video Source Parameters 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Source Selection Video Files 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifying a Video Source File 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Basics
Echo 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Echo Menu 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rounding Errors 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rounding Errors Menu 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Commands and Keywords
Command Format 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Echo and Rounding Errors Remote Commands 3–2. . . . . . . . . . . . . . . . . . . . . . . . .
execute application 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
get keyword [channel-letter] 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
getresults 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
hardkey button_name 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
set keyword [channel_letter] value1 [value2 ...] 3–4. . . . . . . . . . . . . . . . . . . . .
show filename 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
softkey softkey_name 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Get and Set Keywords 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index

Table of Contents
ii VM700T Option 1G Echo and Rounding Errors Measurements User Manual
List of Figures
Figure 1–1: The VM700T Video Measurement Set Configure menu 1–2. . . . . . . . .
Figure 1–2: Configure menus choices 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–3: Echo_Rounding limit menu choices 1–3. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–4: File naming keyboard 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–5: Creating a new file 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–6: Selecting a file to use as a template 1–7. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–1: Echo display 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–2: Echo display the showing Curve 2 graticule 2–2. . . . . . . . . . . . . . . . . .
Figure 2–3: Echo menu tree 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–4: Echo Special Position display 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–5: Rounding Errors display 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–6: Rounding Errors menu tree 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–7: Rounding Errors Special Position display 2–9. . . . . . . . . . . . . . . . . . . .
List of Tables
Table 3–1: VM700T Remote Control Commands Format 3–2. . . . . . . . . . . . . . . . .
Table 3–2: Front Panel Button Names 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–3: Keywords: for get and set commands 3–5. . . . . . . . . . . . . . . . . . . . . . . .

VM700T Option 1G Echo and Rounding Errors Measurements User Manual iii
Preface
The VM700T Video Measurement Set Option 1G (2T Echo and Rounding of
Black & White) gives you access to two measurements, named “Echo” and
“Rounding Errors,” respectively. Echo determines whether or not a signal has too
many echoes. Rounding Errors measures rounding of the black and white signal
levels.
The Echo and Rounding Errors soft keys display in the Measure Mode Video
Options directory window when Option 1G is installed in your VM700T.
To view the Video Options directory window, press the Measure button on the
front panel. If the VM700T was in the Video Options directory when you last
used Measure mode, the Video Options directory displays. Otherwise, touch the
Video Options soft key at the bottom of the display to view the Video Options
directory.
The manual contents are arranged as in the following order:
Configuring the Option describes how to configure the Echo and Rounding
Errors Measurement option of the VM700T Video Measurement Set.
Operating Basics provides information on using the two measurements available
with the VM700T Option 1G, Echo and Rounding Errors. The Echo measure-
ment determines subjectively whether or not a television signal has too many
echoes. Rounding Errors measures the rounding of white level and black level at
specified times from the 50% point of the leading and trailing edge of Bar.
Remote Commands and Keywords describes the remote commands and keywords
that are added to perform the option measurements and get measurement results.
Abbreviated instructions for operating the instrument using remote control are
also found in this section. For complete information about remote control, see
the VM700T RS-232 Interface Programmer Manual.

Configuring the Option

VM700T Option 1G Echo and Rounding Errors Measurements User Manual 1–1
Configuring the Option
The VM700T Video Measurement Set Option 1G (2T Echo and Rounding of
Black & White) gives you access to two measurements, named “Echo” and
“Rounding Errors,” respectively. Echo determines whether or not a signal has too
many echoes. Rounding Errors measures rounding of the black and white signal
levels.
The  and   soft keys display in the Measure Mode Video
Options directory window when Option 1G is installed in your VM700T.
To view the Video Options directory window, press the Measure button on the
front panel. If the VM700T was in the Video Options directory when you last
used Measure mode, the Video Options directory displays. Otherwise, touch the
  soft key at the bottom of the display to view the Video Options
directory.
Configuring the Echo and Rounding Errors option is similar to using the other
video functions of the Video Measurement Set. A series of files and directories
provide default parameters that the VM700T uses to measure video signals. If
your application requires parameters other than the defaults supplied with the
VM700T, you can configure the Echo and Rounding Errors option according to
your preferences.
To configure and use new parameters in Echo and Rounding Errors measure-
ments, you must perform the following tasks:
Create your own Echo and Rounding limits file (for example, )
and configure it with your limits.
Create your own Video Source file (for example, ) and select
Test_Set1 (the new limits file you create) as the limits file to use.
Configure the Source_Selection Video file to select the  file as a
source file for one or all of the channels (A, B, or C) as needed for your
measurements.
The following text describes these configuring steps:
1. Press the Configure button to begin configuration of the Echo and Rounding
Errors option. The screen displays a memory use indicator, information
about instrument option versions, and four soft keys (touch-screen buttons)
as shown in Figure 1–1.

Configuring the Option
1–2 VM700T Option 1G Echo and Rounding Errors Measurements User Manual
Non volatile memory: used 52416 bytes, free 995904 bytes
used
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free
95%
Mā700T ideo Measurement Set xxxxxxĆxxxx
Option 01 NTSC ersion 2.09
Option 11 PAL ersion 2.09
Option 40 Audio ersion 1.05
Option 30 Component ersion 1.01
Option 20 Teletext ersion 1.01
Option 1G Echo/Rounding ersion 1.00
Option 21 Camera Testing ersion 1.02
Keys
Time Configure
Files
Function
Key
Option
Figure 1–1: The VM700T Video Measurement Set Configure menu
2. Touch the Configure Files soft key to display the directories and files for
configuration. The screen displays these directories and files in a window as
shown in Figure 1–2. You can view all the menu choices by turning the front
panel knob to scroll the choices up and down in the window.
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Audio_Limit
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Switch
NTSC/PAL
Print
File
Leave
Directory
In /nvramØ/ConfigFiles
Audio_Source
Files
Audio_Source
Identification
Auto_Limit
Files
Communication
Setup
Component
NTSC Files
Diagnostic
Errors
Diagnostics
Selection
Echo_Rounding Measure_Limit
Files
Measurement
Locations
Camera
Testing
Figure 1–2: Configure menus choices

Configuring the Option
VM700T Option 1G Echo and Rounding Errors Measurements User Manual 1–3
Configuring the Echo Rounding Limits Files
The following text describes the steps needed to configure the VM700T Echo
and Rounding Errors option.
Touch the Echo_Rounding file soft key to enter the Echo Rounding limit file
directory. The screen displays the system default file and (if any have been
created) user limit files (see Figure 1–3). Touching a soft key displays the
parameters in any file; parameters in the System Default file cannot be changed.
If the System Default Echo Rounding limits file is acceptable, the VM700T uses
it (if it is the selected file) to measure input video signals. You can modify the
Echo Rounding limits from the system defaults. Complete the following tasks to
modify Echo Rounding limit file parameters.
Delete Create
File
Print
File
Lea e
Directory
In /n ramØ/ConfigFiles/Echo_Rounding/NTSC
System
Default
RenameSwitch
NTSC/PAL
NTSC Files
Figure 1–3: Echo_Rounding limit menu choices
1. Touch the Create File soft key. The query line (the top line of the display)
asks you to select a file to use as a template for your new file.
2. Touch the soft key of the desired file (for example, System Default).
3. Type a name for your new file on the keyboard that displays (see
Figure 1–4).
Create a Video Limit File
for Echo Rounding

Configuring the Option
1–4 VM700T Option 1G Echo and Rounding Errors Measurements User Manual
Please enter file name (max 31 characters)
qwertyuiop
asdfghj l
Bac
Returnzxcvbnm
Space Shift
Space
Done
Set1 Set2Cancel
Test_Set1
Figure 1–4: File naming keyboard
4. Touch the Done key when you have named the file. The VM700T displays
the new file that contains the Echo and Rounding limits from the file you
selected as the template. You can edit the parameters in this file.
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System
Default
Delete Print
File
Leave
Directory
In /nvramØ/ConfigFiles/Echo~Rounding/NTSC
NTSC Files
Switch
NTSC/PAL Rename
Create
File
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Test_Set1
Figure 1–5: Creating a new file

Configuring the Option
VM700T Option 1G Echo and Rounding Errors Measurements User Manual 1–5
To change any Echo Rounding limit text parameter:
1. In the editable file, rotate the knob to highlight the line that contains the
parameter you want to change. This includes the title line in the configura-
tion file. Use a descriptive title to easily identify it later. (This does not
change the name of the file.)
2. Touch the parameter you want to change. A box highlights the parameter.
3. Rotate the knob to increase or decrease the displayed value for the parameter.
4. Touch the Accept Input soft key to accept the change. The highlight box
disappears, and the new parameter displays.
NOTE. If you change a parameter and do not want to save the change, touch the
No Change & Exit soft key. The VM700T asks you to touch the No Change &
Exit soft key again to verify that you want to exit without changing anything.
To display the file you created, touch its soft key.
When making extensive changes to a file, avoid losing changes by touching the
Update & Exit soft key after each change, then re-entering the file. That way, if
you make a mistake and must exit the file, earlier work is retained while the most
recent change (or mistake) is eliminated.
To delete a modified Echo Rounding limit file:
1. Touch the Delete soft key in the Echo_Rounding files directory. The query
line (the top line of the display) asks you to select a file to delete.
2. Touch the soft key of the file to delete. The file is deleted when its soft key
completely disappears from the screen.
NOTE. Touch the Cancel soft key (replaces the Delete soft key when deletion
begins) to halt the deletion process. You can also halt file deletion by touching
the file soft key.
3. Touch the Leave Directory soft key to return to the Configure menu.
Editing an Echo Rounding
Limit Text Parameter
Deleting a Modified Echo
Rounding Limit File
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