Manual

3-38 Detailed Descriptions of ACL Commands
If <count1> and <count2> resolve to the same microstep position within a given move, the
<new2> value is output approximately 9 microseconds after the <new1> value.
The <new1> value is always output before the <new2> value. If <count2> resolves to an
earlier microstep position than <count1> within a given move, the arithmetic mean (i.e.
average) of the two positions is computed, and <new1> and <new2> are both output at this
intermediate position, spaced approximately 9 microseconds apart.
A zero-length move (for example, due to MR 0,0; two MA's to the same location, or an arc
with zero radius or sweep angle) produces both Digital Outputs changes (if specified),
separated by approximately 9 microseconds.
Only one MD command at a time can be active; an MD cancels the parameters of any
preceding MD. The MD and MM commands should not be used together.
If the machine is in the Emergency Stopped state when an AA, AR, MA, MR, MT, or
Continuous Path move occurs, the motion command is ignored; hence no MD-induced
change occurs at the Digital Outputs. If an Emergency Stop occurs during a move, the
Digital Outputs all go immediately to the False state.
The System precomputes the locations at which the Digital Outputs are to change before
starting each vector, arc, or Continuous Path move. If the move is terminated by a Dynamic
Deceleration (i.e. has come to a complete stop) before a particular Outputs change has
occurred then that change will not occur during this move. See the MN command.
The effects of the MD command can be suspended for a single move or group of moves
through use of the VM command.
The current value being applied to the Digital Outputs can be determined via the OD
command.
For more information about the Digital Outputs see Chapter 8 Using the Digital Outputs and
Inputs.
Example: the command sequence MD 1000,3; MR 4000,4000; produces the following
effect. The MR begins to execute. After 1000 diagonal steps (i.e. 707 steps each in the X
and Y axes), Digital Outputs 0 and 1 become True and all others become False, regardless of
their previous states. (Note that 3 is binary 00000011, which has bits 0 and 1 set).
Example: the sequence MD 500, 255, 255, -200, 0, 7; AR 1000, 0, 360; results in the
following actions. The AR begins to execute; after 500 total steps along the arc, all 8 Digital
Outputs become True; 200 steps before the end, outputs 0, 1, and 2 become False; the
outputs remain unchanged for the remaining 200 steps.
Example: the following two sequences both have the same effect upon vectors and arcs
whose length is less than 32768: MD 0, 255, 255, 32767, 0, 255; and MD -32768, 255,
255, 32767, 0; . The effect is to set all 8 Digital Outputs True at the beginning of each
move, and False at the end. (Note that if no move's length exceeds 32767 then the changes
are "constrained" so they occur at the beginning or end of each vector). If the length is
greater than 32767 the two sequences begin to produce different results.