Tapes; Tape Reader; Tape Code; Leader - Siemens SINUMERIK 880 Programming Manual

05.91
2.6

Tapes

2.6.1

Tape reader

The tape reader must be matched to the control. The data transfer rate and transfer format
(see universal interface) are defined via the setting data.
2.6.2

Tape code

The data on tape are coded according to fixed rules, i.e. a hole combination corresponds to a
particular character. Two tape codes are used: ISO or EIA (see code table).
All characters of a code have a common identification:
• ISO always even number of holes
• EIA always odd number of holes
The control automatically recognizes the correct code as soon as it reads the first % (ISO) or
EOR (EIA). The criterion relating to an odd or even number of holes is used, starting at the
second character of the program, for a character parity check, which has an error detection
rate for single errors of 100%. Each tape must be written in one of the permissible codes. It is
not permissible to change the code within a tape or to splice tapes with different codes; this
will cause the character parity check to respond.
As a further check a complete program comparison is performed if a program already stored in
the program memory is read in again. On detection of an error the read-in process is halted
and the error displayed on the operator panel of the control.
2.6.3

Leader

The leader is used to identify the programs. The tape leader can include all characters except
the start-of-program character (%). The leader is not stored, and is ignored by the control
during program processing.
Shaft % MPF
© Siemens AG 1991 All Rights Reserved
SINUMERIK 880, (PG)
L F
1579
6ZB5 410-0HD02
2 Fundamentals of Programming
2.6 Tapes
2–9