User Guide Owner's manual
5. Calculate the horizontal back porch value. This value is calculated with the formula:
total pixels per line – (active pixels in width + horizontal left border +
horizontal right border + horizontal front porch + horizontal sync width)
Using the values from the example in step 4, above, this equates to:
1800 – (1280 + 0 + 0 + 80 + 128) = 312
6. Enter this value into the Horizontal Back Porch field (see figure 69,
3
).
7. Calculate the correct vertical values for the mode. Assume that the Vertical Top
Border, Vertical Bottom Border, Vertical Front Porch, and Vertical Sync
Width are already correct.
8. Enter the values for Active Lines and Total Lines (see figure 69,
4
) that were
returned in the Telnet session (see step 4, on the previous page).
9. Calculate the vertical back porch value. This value is calculated with the formula:
total lines – (active pixels in height + vertical top border + vertical
bottom border + vertical front porch + vertical sync width)
In the step 4 example, this equates to:
1000 – (960 + 0 + 0 + 3 + 4) = 33
10. Enter this value in the Vertical Back Porch field (see figure 69,
5
).
11. Calculate the pixel clock frequency. This is calculated with the formula:
total lines x total pixels x frame rate
Using the values from step 4, this equates to:
1000 x 1800 x 60 = 108000000
12. Enter this value in the Pixel Clock Frequency field (see figure 69,
6
).
13. Click Update (see figure 69,
7
), and then click Save Formats (see figure 69,
8
). The
new mode should now be an exact match for the connected source.
14. To test the new mode select the Display tab for the decoder, and ensure that Auto is
selected in the Output Format selector.
15. Switch the resolution on the source to a different resolution and then switch it back
again. The mode should display. If it does not, see the Troubleshooting Guide on
page117.
VNM 250 • Configuration with the VNM 250 GUI 86