Link-up and update
12.4 Time monitoring
S7-400H
166
System Manual, 03/2012, A5E00267695-11
12.4.3
Performance values for link-up and update
User program share T
P15_AWP
of the maximum inhibit time for priority classes > 15
The user program share T
P15_AWP
of the maximum inhibit time for priority classes > 15 can be
calculated using the following formula:
T
P15_AWP
in ms = 0.7 x size of DBs in work memory in KB + 75
The table below shows the derived times for some typical values in work memory data.
Table 12- 3 Typical values for the user program part
Work memory data
T
P15_AWP
500 KB
220 ms
1 MB
400 ms
2 MB
0.8 s
5 MB
1.8 s
10 MB
3.6 s
The following assumptions were made for this formula:
●
80% of the data blocks are modified prior to delaying the interrupts of priority classes >
15.
In particular for fail-safe systems, this calculated value must be more precise to avoid any
timeout of driver blocks (see section Determining the monitoring times (Page 159)).
●
For active or queued communication functions, allowance is made for an update time of
approximately 100 ms per MB in the work memory occupied by data blocks.
Depending on the communication load of your automation system, you will need to add or
deduct a value when you set T
P15_AWP
.
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 ...