Link-up and update
12.3 Link-up and update sequence
S7-400H
150
System Manual, 03/2012, A5E00267695-11
8.
Generating the start event for the cyclic interrupt OB with special handling.
Note
The cyclic interrupt OB with special handling is particularly important in situations where
you need to address certain modules or program parts within a specific time. This is a
typical scenario in fail-safe systems. For details, refer to the
S7-400F and S7-400FH
Automation Systems and S7-300 Automation Systems, Fail-safe Signal Modules
manuals.
To prevent an extension of the special cyclic interrupt, the cyclic alarm OB with special
handling must be assigned top priority.
9.
Transfer of outputs and of all data block contents modified again. Transfer of timers,
counters, bit memories, and inputs. Transfer of the diagnostic buffer.
During this data synchronization, the system interrupts the clock pulse for cyclic
interrupts, time-delay interrupts and S7 timers. This results in the loss of any synchronism
between cyclic and time-of-day interrupts.
10.
Cancel all restrictions. Delayed interrupts and communication functions are executed. All
OBs are executed again.
A constant bus cycle time compared with previous calls can no longer be guaranteed for
delayed cyclic interrupt OBs.
Note
Process interrupts and diagnostic interrupts are stored by the I/O devices. Such interrupt
requests issued by distributed I/O modules are executed when the block is re-enabled.
Any such requests by central I/O modules can only be executed provided the same
interrupt request did not occur repeatedly while the status was disabled.
If the PG/ES requested a master/standby changeover, the previous standby CPU assumes
master mode and the previous master CPU goes into STOP when the update is completed.
Both CPUs will otherwise go into RUN (redundant system mode) and execute the user
program in synchronism.
When there is a master/standby changeover, in the first cycle after the update OB 1 is
assigned a separate identifier (see
System Software for S7-300/400, System and Standard
Functions Reference Manual). For information on other aspects resulting from modifying the
configuration, refer to section Switch to CPU with modified configuration or expanded
Содержание SIMATIC S7-400H
Страница 24: ...Preface 1 1 Preface S7 400H 24 System Manual 03 2012 A5E00267695 11 ...
Страница 46: ...Getting Started 4 5 Special layout features of SIMATIC Manager S7 400H 46 System Manual 03 2012 A5E00267695 11 ...
Страница 120: ...Memory concept 10 1 Overview of the memory concept of S7 400H CPUs S7 400H 120 System Manual 03 2012 A5E00267695 11 ...
Страница 258: ...Communication 14 8 General issues regarding communication S7 400H 258 System Manual 03 2012 A5E00267695 11 ...
Страница 354: ...Synchronization modules 18 3 Selecting fiber optic cables S7 400H 354 System Manual 03 2012 A5E00267695 11 ...
Страница 434: ...Technical data 20 6 Runtimes of the FCs and FBs for redundant I Os S7 400H 434 System Manual 03 2012 A5E00267695 11 ...
Страница 460: ...Function modules and communication processors supported by the S7 400H S7 400H 460 System Manual 03 2012 A5E00267695 11 ...