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 Z300.0 ; 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 vertically. 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 P/S alarm (No.002) is
output. No TV check is made only for those parts that are skipped by the
label skip function. Bit 1 (CTV) of parameter No. 0100 is used to specify
whether comments enclosed in parentheses are counted as characters
during TV check. The TV check function can be enabled or disabled by
setting on the MDI unit (See III–11.4.3.).
D Sequence number and
D TV check (Vertical parity
check along tape)