Tektronix SDA601, Service Manual

Page: 38 / 132

Operating Information
2- 16 SDA 601 Serial Digital Analyzer
Video format EDH packet found/missing
Line standard (625 or 525) Audio present/missing
Video present or missing Stuck bits (if any)
Bits in active picture (8 or 10) Other ANC (if any)
The twelve remaining conditions are organized into the four Watch groups:
Data Value Group: CRC Change Group:
Illegal (word) values APCRC changes (yes/no)
Video In/Out of range FFCRC changes (yes/no)
Format Group: APCRC is/not Ø
Line/field length (OK/incorrect)
EDH Group:
ANC Format (OK/incorrect) AP EDH errors (yes/no)
TRS (OK/incorrect) FF EDH errors (yes/no)
Zero length ANC (yes/no) EDH flag set/not set
When only the Data Value group is set to “Watch,” then, the SDA601 will
actually observe the status of ten conditions—the eight default conditions,
plus Illegal Values and Video In/Out of Range. If all four groups are selected,
all 20 conditions will be monitored.
Group selection can be inconvenient in some circumstances, however. An
example is observing a changing test signal that is being generated with
ØAPCRC. In this case, FFCRC changes are not an error, but a non-zero
APCRC is. Watching the CRC Change Group, then, could result in
inappropriate or misleading alarms.
To prevent this conflict, set the Watch Menu Type to “Item Select” through
the Utility menu and select the “AP CRC Not Ø” item through the Watch
Menu. To set the Watch Menu Type:
a. Hold the Lock Out key down and press the ON button to enter the Utility
menu. Release the
ON
button, but continue to press the
Lock Out
key until
the display resembles Figure 2--11.
Figure 2- 11: The Initial SDA601 Utility Menu Display
b. Go to the Watch Menu Type menu item by pressing the B key three
times.
c. Press the " key once to choose Item Select, then press
ENTER
to confirm
the choice.
d. Press
Watch
to exit the Utility menu.