Use Sqi Without Sqo - Allen-Bradley Logix5000 Reference Manual

Example:
When enabled, the SQI instruction passes value_2 through the mask to
determine whether the result is equal to the current element in array_dint. The
masked comparison is true, so the rung-condition-out goes true.
SQI Operand
Source
Mask
Array
A 0 in the mask means the bit is not compared (designated by sextets in
this example).

Use SQI without SQO

If you use the SQI instruction without a paired SQO instruction, you have to
externally increment the sequencer array.
The SQI instruction compares the source value. The ADD instruction increments the sequencer array. The GRT determined whether another value is available to check in the sequencer array. The MOV instruction resets the position value after completely stepping through the sequencer array one time.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Sequencer Instructions (SQI, SQO, SQL)
Example Values (DINTs Displayed In Binary)
xxxxxxxx xxxxxxxx xxxx0101 xxxx1010
00000000 00000000 00001111 00001111
xxxxxxxx xxxxxxxx xxxx0101 xxxx1010
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