Manual

3-8 Detailed Descriptions of ACL Commands
BC [<re-use>] Begin Continuous Path
This command denotes the beginning of a Continuous Path sequence. All ACL commands
following this command, up until the next EC ("End Continuous Path") are part of this
Continuous Path sequence. Any XY motion commands within the Continuous Path
sequence are performed as a single move with one acceleration phase, possibly one slew
phase, and one deceleration phase. The motion does not begin until the EC command is
received.
The following commands may occur between BC and EC:
Physical action commands:
AA, AR, CD, MA, MR, SP, TD.
Non-action commands:
BP, CF, EP, IN, OC, OE, OF, OI, OL, OO, OP, OR, OS, OU, PS, SO, XD.
A maximum of 200 physical action commands may occur in one BC...EC sequence. The
number of non-action commands is unlimited.
The IN command cancels the BC and all intervening commands.
The output commands OC through OU execute immediately and do not become part of the
BC...EC motion sequence. The same holds true of the PS command; the machine pauses
after executing that command, but before the continuous motion has begun.
Repeating The Sequence
Normally there is a precomputation delay as the physical action commands are processed,
before motion begins. (See "Delays, Emergency Stop, ...", below.) If the same BC...EC
sequence is to be repeated exactly, this delay can be eliminated by specifying a nonzero
value for the <re-use> parameter. In this case, no EC is required. The sequence may be
repeated any number of times (e.g., via BC1; BC1; BC1; ...) as long as the following
conditions are met.
The previous BC...EC sequence can be re-used only if: the carriage is in exactly the same
location it occupied at the previous BC; and no errors occurred in the previous sequence.
Note that arcs may introduce small position errors (see "Position Errors", below); therefore,
it may be necessary to put an MA command before the repeated BC to ensure exactly the
right carriage location. (Note that the MA won't help if it is within the BC...EC.)
A repeated BC...EC sequence is performed at the same speed and acceleration as the original
sequence, regardless of any intervening AC, SR, or VM commands.
If the <re-use> parameter is zero or is omitted then the BC is "normal" and must be
followed by motion commands and EC.