Allen-Bradley MicroLogix 1200 Reference Manual page 207

This instruction uses the following operands:
• File - This is the sequencer reference file. Its contents, on an
element-by-element, basis are masked and stored in the destination.
If file type is word, then mask and source must be
NOTE
words. If file type is long word, mask and source
must be long words.
• Mask - The mask operand contains the mask value. When mask bits
are set to 1, data is allowed to pass through to destination. When
mask bits are reset to 0, the data is masked (does not pass through to
destination). The immediate data ranges for mask are from 0 to
0xFFFF (word) or 0 to 0xFFFFFFFF (long word).
If mask is direct or indirect, the position selects the
NOTE
location in the specified file.
• Destination - The destination operand is the sequencer location or file.
• Control - This is a control file address. The status bits, stack length,
and the position value are stored in this element. The control element
consists of 3 words:
15 14 13
Word 0 EN (1) -- (2)
DN
Word 1 Length - contains the index of the last element in the sequencer reference file
Word 2 Position - the current position in the sequence
(1) EN - Enable Bit is set by a false-to-true rung transition and indicates that the instruction is enabled.
(2) DN - Done Bit is set after the instruction has operated on the last word in the sequencer file. It is reset on the next
false-to-true rung transition after the rung goes false.
(3) ER - Error Bit is set when the controller detects a negative position value, or a negative or zero length value. When the
ER bit is set, the minor error bit (S2:5/2) is also set.
• Length - The length operand contains the number of steps in the
sequencer file (as well as Mask and/or Destination if they are file data
types). The length of the sequencer can range from 1 to 256.
• Position - This is the current location or step in the sequencer file (as
well as Mask and/or Destination if they are file data types). It
determines the next location in the stack to be masked and moved to
the destination. Position is a component of the control register. The
position can range from 0 to 255. Position is incremented on each
false-to-true transition.
12 11 10 9 8
-- (3) not used FD not used
ER
Sequencer Instructions 15-7
7 6 5 4 3 2 1 0
Publication 1762-RM001C-EN-P