13. PROGRAM CONFIGURATION
A program consists of several commands. One command unit is called a
block. One block is separated from another with an EOB of end of block
Table 13.2 (a) EOB code
Notation in this
End of block (EOB) LF CR ;
At the head of a block, a sequence number consisting of address N
followed by a number not longer than five digits (1 to 99999) can be
placed. Sequence numbers can be specified in a random order, and any
numbers can be skipped. Sequence numbers may be specified for all
blocks or only for desired blocks of the program. In general, however, it
is convenient to assign sequence numbers in ascending order in phase
with the machining steps (for example, when a new tool is used by tool
replacement, and machining proceeds to a new surface with table
N300 X200.0 Y300.0 ; A sequence number is underlined.
Fig.13.2 (b) Sequence number and block (example)
N0 must not be used for the reason of file compatibility with
other CNC systems.
Program number 0 cannot be used. So 0 must not be used
for a sequence number regarded as a program number.
A parity check is made for a block on input tape horizontally. If the
number of characters in one block (starting with the code immediately
after an EOB and ending with the next EOB) is odd, an alarm (No.002)
is output. No TV check is made only for those parts that are skipped by
the label skip function. A comment section enclosed in parentheses is also
subject to TV check to count the number of characters. The TV check
function can be enabled or disabled by setting on the MDI unit (See
Subsec. 11.4.3 in Part III.).
D Sequence number and
D TV check (Vertical parity
check along tape)