Справочник Пользователя для Siemens 505-2557
Advanced Function Programming
3-18
SIMATIC 505–2557 Installation and Operation Guide
3.4
Timing Considerations
Without any of the advanced features enabled, the SIMATIC 505–2557
module will update all 16 points in less than 6 msec. With all functions
enabled for all 16 points, the module will update all 16 channels in less than
56 msec. Each function has a specific overhead associated with it and your
application should consider the time delays to ensure that there is adequate
time allowed for the processing of data.
module will update all 16 points in less than 6 msec. With all functions
enabled for all 16 points, the module will update all 16 channels in less than
56 msec. Each function has a specific overhead associated with it and your
application should consider the time delays to ensure that there is adequate
time allowed for the processing of data.
Table 3-7 shows a chart of the overhead required for all 16 channels when
each of the advanced functions is enabled. Operations such as scaling and
offset mode require the greatest amount of time due to the multiplication
and division in the microcomputer.
each of the advanced functions is enabled. Operations such as scaling and
offset mode require the greatest amount of time due to the multiplication
and division in the microcomputer.
Table 3-7
Timing Overhead for Functions Enabled
Functions Enabled in Enhanced Mode
(32 WX and 32 WY, 16 X and 16 Y)
(32 WX and 32 WY, 16 X and 16 Y)
Time for All 16
Channels
Channels
None
6.5 msec
Low alarm
7.73 msec
High alarm
7.73 msec
Scaling
27.1 msec
Offset mode
27.1 msec
Filtering
8.97 msec
Averaging
7.85 msec
Averaging reset (16 channels)
41.8 msec
Peak hold
7.65 msec
Valley hold
7.65 msec
16 WX MODE
No digital filtering
5.80 msec
Filtering enabled
8.20 msec
Timing Constraints
When Using
Advanced
Functions
When Using
Advanced
Functions