Manual

Detailed Descriptions of ACL Commands 3-71
V< <varid>, <value> Variable Less Than
This command tests whether the contents of the variable whose i.d. is given by <varid> is
numerically less than the specified <value>. The test result is available to the next ON, XI,
XU, or XW command; bit 0 will be "1" if and only if the test was True (i.e. the variable was
less than <value>). (The other 7 bits will be seen as "0".) For example:
V< 5, 100; XW 22, 1;
executes Download Sequence 22 while variable 5 contains any value less than 100.
If an IN ("Initialize") command occurs after the V< but before any ON, XI, XU, or XW, the
effect of the V< is canceled.
For program clarity, the V< should be immediately followed by the ON, XI, XU, or XW. In
any case, if the V< is in a Download Sequence, the ON, XI, XU, or XW must be in the same
Download Sequence. The ON, XI, XU, or XW must not be in a Download Sequence called
by the one containing the V<, and must not be in a Download Sequence which called the one
containing the V<.
If <value> is specified as an at-sign "@" and another <varid>, say, variable 2, then the
value of this second variable is captured only once, at the time the V< command is executed.
This means that an XU or XW will always test against the original value of variable 2, even
if that variable has changed since the V< was executed.
Note that V< does not affect the WN ("Wait For Digital Inputs") command.
V= <varid>, <value> Variable Equal To
This command is similar to the V< command, but instead tests whether the variable's
contents are equal to the specified <value>. Bit 0 in the following ON, XI, XU, or XW will
be "1" if the equality is True.
You should use caution when comparing two computed values for equality; small roundoff
errors could result in unexpected inequality of two numbers that are very close to one
another.
V> <varid>, <value> Variable Greater Than
This command is similar to the V< command, but instead tests whether the variable's
contents are greater than the specified <value>. Bit 0 in the following ON, XI, XU, or XW
will be "1" if the greater-than comparison is True.
V+ <varid>, <value> Variable Add
This command adds a specified value to the variable whose i.d. is given by <varid>.
Saturation arithmetic is used; in other words, the result is never greater than 32767.9999 or
less than -32768.0000. If the correct result of the addition would have been outside of this
range, an error is logged and the variable is set to the highest or lowest possible value.