Specifications

4-4
Operating Features and Specifications
Patterns
Zero Substitution
Zeros can be substituted for data to extend the longest run of zeros in the above patterns.
The longest run can be extended to the pattern length −1. The bit following the substituted
zerosissetto1.
Variable Mark Density
The ratio of 1s to total bits in the above patterns can be set to 1/8, 1/4, 1/2, 3/4, or 7/8.
User-programmable test patterns
Variable length user patterns from 1 bit to 8M bits. Refer to Chapter 8 User Patterns and
Disk Operation andAppendixB,pageB-3,fordetailedinformationonuserpatterns.
Alternate test pattern - pattern generator only
Switch between two equal length user programmable patterns, each up to 4,194,304 bits,
under the control of a front panel key, GPIB or the auxiliary input port; changeover is
synchronous with the end of a word. The length of the alternating patterns should be a
multiple of 256 bits.
Two methods of controlling pattern changeover are available, oneshot and alternate. Refer
to the paragraph on the Auxiliary Input (on page 4-10) for further information.
NOTE The error detector is not affected by the pattern switching and is set to
pattern A when Alternate Pattern is selected.
Table 4-1 Pattern Granularity
Pattern Length Alternate Pattern Length Resolution
>4 Mbit >2 Mbit 256
>2 Mbit >1 Mbit 128
>1 Mbit >512 kbit 64
>512 kbit >256 kbit 32
>256 kbit >128 kbit 16
>128 kbit >64 kbit 8
>64 kbit >32 kbit 4
>32 kbit >16 kbit 2
≤32 kbit ≤16 kbit
1