How do I get the VM700T to perform DPDG measurements on an NTC7 composite test signal?
The VM700T defaults to looking for the modulated staircase test signal on line 17 of the vertical interval; this is traditionally where this test signal is placed in broadcast television. In the case of the NTC7 composite test signal, the staircase appears on all lines of active video and NOT in the vertical interval, therefore the VM700T will give you a "no VITS" error. In order to perform this measurement in the auto mode you will need to reconfigure the VM700T to check for this test signal somewhere in the active picture region. To configure the VM700T this way, follow these steps:
1) Press the "Configure" key to bring up the configuration menu, then touch the "Configure Files" button to enter the VM700T configuration files directory.
2) Touch the "Measurement Locations" button and either modify an existing measurement location file (you cannot modify the "System Default" file) or create a new one by touching the "Create File" button. If you create a new measurement location file, you will be prompted to select a template, touch the "System Default" file to use this as a template, then you will be requested to enter a name for this file, once you have entered the name you will then be allowed to modify the settings (see next step).
3) Once inside the measurement location file, use the general purpose knob to scroll down within the file until you see the "Auto Mode" heading. Under this heading, change the "Composite", "Multiburst" and "NTC-7 Combination" values to some line within the active picture region (for example, line 50). To change these values, scroll down to the line you wish to change, then touch the value you wish to change and a box will appear around that value, now use the general purpose knob to modify the value. When you are done modifying the value, touch the "Accept Input" button or simply touch anywhere outside the currently selected value. When you're done modifying all the values you wish to change on this page, touch the "Update & Exit" button to save your changes.
4) Touch the "Leave Directory" button to go back to the configure files directory.
5) Touch the "Video Source Files" button to enter the video source files directory. Either modify one of the existing files here or create a new one using the same steps as above.
6) Once you are in the file, scroll down to the line labeled "Measurement Location File" and modify that value to point to the file you created (or modified) in step 2. Most of the other settings can be left set to "System Default" or in the case of the auto limits file "EndToEnd" works well.
7) Once you are done selecting your measurements location file, touch the "Update & Exit" button to save and then touch the "Leave Directory" button to go back to the configuration files directory.
8) Finally, touch the "Source_Selection Video" button to open the source selection file, scroll down to the line corresponding to the input you're using (A, B or C) and modify that value to point to the video source file you created in step 5. Touch "Update & Exit" to save your changes.
Now when you run the Auto mode the VM700T will look for the modulated staircase on line 50 (or whichever line you chose in step 3) instead of the vertical interval and the tests should now work.
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FAQ ID 63571View all FAQs »