Anritsu BERTWave MP2100B, Руководство по эксплуатации, Страница: 173 / 382

6.3 Setting Conditions for Error Detection
6-13
6
Measuring Bit Error
To shorten the pattern sync time when SYNC Control is ON, set the value
of the 64-bit string which is not duplicate in other portion in the same
string to Frame Position in programmable pattern.
The pattern synchronization takes much time if there are multiple 64-bit
strings, which is the same as 64-bit string used for the same string
synchronization detection.
+0 +1 +2 +3 +4 +5 +6 +7 +8 +9 +A +B +C +D +E +F
000000 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55
000010 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55
000020 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55
000030 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55
000040 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
000050 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
000060 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
000070 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
000080 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
000090 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F
0000A0 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F
0000B0 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F
Figure 6.3-4 Programmable Pattern Example 1
Figure 6.3-5 shows an example of programmable pattern when pattern
length is 1536 bits.
In this example, 64 bytes from the programmable pattern header have
the same value of 0x55, so the header 512 bits is a repeating pattern of
alternating 1s and 0s.
When Frame Position is set to 1 in this programmable pattern, the 8
bytes of data from address 0x000000 to address 0x000007 are used to
detect pattern synchronization.
There are 224 points between address 0x000000 and address 0x000038
with these 8 bytes match. The data remaining after these 8 byte data
matches is compared and the proportion of matched bits in the entire
programmable pattern is 1:224. When pattern synchronization processing
is performed with this type of pattern, the time required to obtain
synchronization becomes longer.