Microtest TSB-67 - 568A Annex E - Manual (Page 15)

Page 15
Press the ESCAPE key to exit.
Editing the Cable Type
To display the EDIT CABLE screen, press Cable (F1) from the Ready screen, then press Edit
(F2). This screen displays the characteristics of the cable you will be testing.
Press the
Ñ
or
Ò
arrow key to highlight the (cable) Name or NVP (Nominal Velocity of
Propagation) field. The Impedance field is for reference only and does not affect test results. The
highlighted field will be enclosed in a box. Use the Scanner keypad to enter the Cable Name or the
NVP value.
Press Del (F2) to delete the character at the cursor.
If your Scanner has an alphanumeric overlay on the keypad, use the keypad to enter the cable
name. If your Scanner does not have an alphanumeric overlay, press
Edit (F2) to edit the name. See
Chapter 4: Editing, Printing & Updating for more information on editing.
Note: If you change the information for a factory supplied cable type and do not edit the cable
name, an asterisk (*) will appear before the cable name.
If you are not sure of the NVP value, press
GetNVP (F4) to calculate it. See Calculating NVP for
more information.
Press Save (F1) to store the new settings and exit. If you have changed the cable information,
press Default (F1) from the CABLE SETUP screen to select it as the cable type to use during
testing.
Press the ESCAPE key to exit without saving.
Calculating NVP
To display the CABLE NVP screen, press Cable (F1) from the Ready screen, then press Edit
(F2); then press GetNVP (F4).
For an accurate Length test, the NVP (Nominal Velocity of Propagation) must be set correctly.
NVP is a measure of how fast a signal travels down a cable compared to the speed of light. It is
usually between 60% and 90% and is specified by the cable vendor. The Scanner has a large library
of cables with the manufacturer’s specified NVP.
This screen lets you calculate the NVP for cables over 50 feet (15.24 meters) long. The
PentaScanner and PentaScanner Cable Admin calculate the NVP based on the longest wire
pair in the cable. The PentaScanner+ calculates the NVP based on the shortest wire pair in the
cable.
You can use the CABLE NVP feature to create a custom cable type when the cable type is not
known.
If your Scanner has an alphanumeric overlay on the keypad, use the keypad to enter the cable
length. If your Scanner does not have an alphanumeric overlay, press
Edit (F2) to edit the length.
See Chapter 4: Editing, Printing & Updating for more information on editing.
Press Del (F2) if you wish to delete the character at the cursor. After you have entered the cable
length, press Calc (F4) to calculate the NVP.