Allen-Bradley MicroLogix 1200 Reference Manual page 203

The following figure explains how the SQC instruction works.
Word
B10:11
B10:12
B10:13 0010
B10:14
B10:15
SQC FD bit is set when the instruction detects that an input word matches
(through mask) its corresponding reference word.
The FD bit R6:21/FD is set in the example, since the input word matches
the sequencer reference value using the mask value.
SQC SQC
EN
Sequencer Compare
File #B10:11
Mask FFF0 DN
Source I:3.0
Control R6:21 FD
Length 4<
Position 2<
Input Word I:3.0
0010 0100 1001 1101
Mask Value FFF0
1111 1111 1111 0000
Sequencer Ref File #B10:11
0100 1001 0000
Sequencer Instructions 15-3
Step
0
1
2
3
4
Publication 1762-RM001C-EN-P