Differences between fault-tolerant systems and standard systems
S7-400H
System Manual, 03/2012, A5E00267695-11
455
Restrictions of the fault-tolerant CPU compared to a standard CPU
Function
Restriction of the fault-tolerant CPU
Hot restart
A hot restart is not possible. OB 101 is not possible
Multicomputing
Multicomputing is not possible. OB 60 and SFC 35 are not
supported
Startup without configuration
loaded
Startup without loaded configuration is not possible.
Background OB
OB 90 is not supported.
Multi-DP master mode
The fault-tolerant CPUs do not support multi-DP master mode in
REDUNDANT mode.
Direct communication between
DP slaves
Cannot be configured in STEP 7
Constant bus cycle time for DP
slaves
No constant bus cycle time for DP slaves in the fault-tolerant
system
Synchronization of DP slaves
Synchronization of DP slave groups is not supported. SFC 11
"DPSYC_FR" is not supported.
Disabling and enabling DP
slaves
Disabling and enabling DP slaves is not possible. SFC 12
"D_ACT_DP" is not supported.
Runtime response
The command execution time for a CPU 41x–5H is slightly higher
compared to the corresponding standard CPU (see
S7–400
Instruction List
and
S7-400H Instruction List
). This must be taken
into account for all time-critical applications. You may need to
increase the scan cycle monitoring time.
DP cycle time
A CPU 41x-5H has a slightly longer DP cycle time compared to
the corresponding standard CPU.
Delays and inhibits
During update:
The asynchronous SFCs for data records are acknowledged
negatively
Messages are delayed
All priority classes up to 15 are initially delayed
Communication jobs are rejected or delayed
Finally, all priority classes are disabled
For more detailed information, refer to chapter 7.
Use of symbol-oriented
messages (SCAN)
The use of symbol-oriented messages is not possible.
Global data communication
GD communication is not possible (neither cyclically, nor by
calling system functions SFC 60 "GD_SND" and SFC 61
"GD_RCV")
S7 basic communication
Communication functions (SFCs) for basic communication are not
supported.
S5 connection
The connection of S5 modules by means of an adapter casing is
not possible. The connection of S5 modules via IM 463-2 is only
supported in stand-alone mode.
CPU as DP slave
Not possible
CPU as I-Device
Not possible
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 ...