Magni MM-410, Руководство оператора, Страница: 115 / 182

Automatic Measurement (AVM-510A)
9-9
Under the main MEASUREMENT menu is a sub-menu called MULTIBURST ID. This is the key to
multiburst signal detection when using AUTOMEASURE/AUTO MEAS SET. Three selections under
MULTIBURST ID are available:
•
STANDARD (FCC multiburst or CCIR 18)

If the AVM-510A detects a multiburst signal of
any kind, it assumes it is one of these two standards, depending on the line rate of the signal.
•
CUSTOM

This is a non-standard, custom multiburst that you define as described in the
following section “Setting Timing for Multiburst.” If the AVM-510A detects a multiburst of any
kind, it assumes it is a custom multiburst, and will take measurements according to the timing and
frequency established under the FREQUENCY RESP menus MULTIBURST TIMINGS and
PACKET FREQUENCIES.
•
AUTO DETECT

When selected, the AVM-510A automatically chooses between STANDARD
or CUSTOM. If the AVM-510A senses that the multiburst is one of the standards, it applies the
built-in timing and packet frequencies. If the AVM-510A senses a multiburst that is not standard,
it applies the custom timing and packet frequencies.
When using the Frequency Response measurement set and the Frequency Response signal ID is set to
AUTO SIG ID, the MULTIBURST ID has control, just as it does when AUTOMEASURE/AUTO MEAS
SET is used.
If the Frequency Response signal ID is set to anything other than AUTO SIG ID, it forces the AVM-
510A to recognize the signal as it is named by the Frequency Response signal ID.
Setting Timing for Multiburst
Multiburst signals are variable. They have different frequency packets that start at different points
along the line. The peak-to-peak amplitudes vary from one standard multiburst signal to another. The
AVM-510A lets you set up a custom standard for a non-standard multiburst signal and apply all the
parameters of the Frequency Response measurement set to it.
This section explains how to set variables for a custom multiburst signal. To set the variables, use the
following two-step process:
NOTE: Prior to setting variables, the AVM-510A is used to determine the starting time
(from the leading edge of sync) of the bar, the pedestal, and each frequency burst or
packet, and the frequency of each packet.