Startup - Siemens SIMATIC S5 IP 281 Equipment Manual

Programming Example

Startup

The module must be parameterized during startup, The module is not equipped with a buffer.
Since the parameterization is lost when a power failure occurs or the module is switched off, the
formed.
OB 21 OB 21 is processed during a manual new start (PG selection and operating
mode switch STOP+ RUN). It calls startup block FB 20 and working (para-
OB 22 OB 22 is processed when a restart is performed due to return of voltage
(power-on). It is identical to OB 21.
The following is performed in the startup FB.
FB 20
– The register addresses (basic address +0 to basic address +7) are cal-
– The parameter register and control register aretransferred from DB20to
– The parameterization bit is set.
Keep the following in mind.
– Control register 3 must be transferred after parameterization (set para-
– When setting the autonomous operating modes (except CONC), the
– When CPU 944A/B is used, the correct addressing sequence must be
DB 20 is used as parameterization DB and working DB. The addresses
DB 20
(128 +0 to 128 +7) calculated during startup are entered in DW O to DW 7.
In addition, the register contents are stored for the startup in DB 20 (DW 8
to DW 12),
All other register accesses (read and write accesses) are also performed
via this DB (DW 13 to DW 30).
DW31 isthestorage Iocation forsavingthe register set address during read
and write accesses. The interrupt program accesses this location to update
the register set selection again after an interrupt is processed.
7 – 4
culated and stored in DB 20 to simplify addressing in the cyclic program.
the 1P 281.
GEN bit must first be set in control register 1/2 for the gate enable, and
then the parameter register. Otherwise the ERROR LED goes on.
adhered to.
R 11/92