Siemens SINUMERIK 880 SW 6 Planning Manual page 40

1 General Overview
1.3.4 Provision of basic signals
The figure below illustrates the structure of the flag area. The flag area FY 25 - FY 255 is
available to the user.
The following points must be observed here:
• Interface signals for bit-by-bit processing can be copied between the flag area FY 25 -
FY 223 and data blocks with the function macros FB 70 and FB 71. (Function macros are
FBs that are integrated in the operating system.) The user must split up this area himself,
that is to say he must specify the area between FY 25 and FY 223 that is to be or can be
used for dynamic auxiliary flags. Some restrictions apply when using certain FBs (see
below).
• The flag area FY 224 to FY 225 or FY 200 to FY 255
the operating system when the processing level changes. This flag area is also restored
after a restart.
• The flag area FY 200 to FY 255 is used to some extent by function blocks (see FB
descriptions, also SIMATIC FBs where applicable). The following exceptions apply here: no
assignment of dummy parameters. The conditions of the flags may have to be saved by
the user when leaving the block. If these function blocks are not utilized by the PLC user
program, these flags are at the free disposal of the user.
FY
199
200
224
255
Structure of flag area
_______
d) with GA2, software version 1 and higher
1–26
0
Basic signals
24
25
e.g. Auxiliary flags or
dynamically assignable
by interface signals (FB 70,
FB 71)
Free for user
Reserved for function blocks
Saved area with level change or
restart
© Siemens AG 1991 All Rights Reserved
d)
(if MD 6026.3 is set) is saved by
6ZB5 410-0HE02
SINUMERIK 880 (PJ)
01.93