Table of Contents
Advertisement
Integral Blocks
11.2
Organization Blocks
Besides function blocks, organization blocks are also integrated in the CPUs of the S5-115U
programmable controller.
11.2.1 OB31 Scan Time Triggering
A scan time monitor monitors the program scan time. If program scanning takes longer than the
specified scan monitoring time (e.g., 500 msec.), the CPU enters the
This situation can occur, for instance, when
•
The control program is too long.
•
The program enters a continuous loop.
The scan time monitor can be started at any point in the control program using the OB31 call
(JU OB31), i.e. the scan monitoring time is restarted.
Prerequisite: SYSTEM OPERATIONS enabled on the programmer.
The scan monitoring time can be set in the following ways:
•
In system data word 96 (EAC0
•
In DB1 (see Section 11.3).
11.2.2 OB160 Variable Time Loop
OB160 simulates operation execution times. This makes you independent of the different opera-
tion execution times of the various CPUs and you can program wait times uniformly for all CPUs of
the S5-115U range.
Proceed as follows:
The waiting time must be loaded into the ACCUM in µsec. (range: 120 to 65535 or 78
Example:
A waiting time of one millisecond is to be programmed.
L
KF +1000
JU OB 160.
Please note the following when programming OB160:
A process interrupt (OB2 to OB5) and the timed interrupt (OB6) can interrupt the waiting time
(provided no interrupt disable (IA) has been programmed). The waiting time stops during the in-
terrupt! Similarly, the waiting time is increased by running PG/OP operations. The times set are
therefore minimum times!
OBs 10 to 13 cannot interrupt OB160!
*In the case of CPU 944: 190 µs
11-32
) (see Chapter 2)
H
S5-115U Manual
"
"
STOP
mode.
to FFFF
H
EWA 4NEB 811 6130-02b
).
H
Advertisement
Table of Contents
