Siemens SIMATIC S5 - Interruptprocessing

Programming Instructions
R 02/92
9.3.8 Interrupt Processing
If one of the setpoints or a zero shift value is to receive an interrupt identification, the module must
be preset to a group interrupt bit of the input byte IB or to an interrupt line by means of jumper
setting. (See operating instructions of the individual programmable controllers.)
To ensure that in case of programmable controllers with group interrupt
(S5– 150U/S, S5– 155U in
S5– 150U mode) the respective interrupt block is processed only once (only for the rising edge of
the interrupt signal) via input byte
IB O, the number of this group interrupt bit must be specified at
parameter ABIT:
ABIT : ~ = X, y
X = 255, y = 255 Module without interrupt
x = o, y = o to 7 Reset of the correlated interrupt bit in the
system data
If this bit is not reset in the system data of the respective programmable controllers, the corre-
sponding alarm block is processed again when the interrupt signal disappears.
(S5–155U: in
S5–150U–mode an interrupt is evaluated via the input byte IB O depending on the edge; in
S5– 155U –mode the evaluation via the interrupt lines depends on the level).
If an interrupt occurs (in accordance with the jumper setting), a block of the interrupt–controlled
processing is called.
This block contains the call for function block FB 157 with the parameter assignment BEF=KB.
After the call, the parameter ST indicates from which channel the interrupt arrived. Now a special
interrupt program can be processed.
If an interrupt occurs during processing of function block FB 157 in the cyclic program, the group
interrupt at the bus is deleted again in FB 157 when byte 7 is read. Consequently no organization
block of the interrupt–controlled processing is called. The function block, however, updates the
control bits so that subsequently an interrupt program can be called depending on the interrupt
bits.
9 – 28
1P 241 Equipment Manual
@ Siemens AG 1989, Order No.: 6E.S5 998-0KD21
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com