| time of 20 ms. The analog on-board I/O supplies a measured value to the CPU every |
|
| millisecond within the integration timeThe following figure shows how this works using a 10 Hz interference frequency suppression |
|
as an example. A 10 Hz interference frequency suppression corresponds to an integration
time of 100 ms. The analog on-board I/O supplies a measured value to the CPU every |
|
millisecond within the integration time.The following table provides an overview of the configurable line frequencies, the integration
time and the intervals within which measured values are supplied to the CPU.
Table C- 1 Overview of the configurable line frequenciesData record structure
The figure below shows the structure of data record 64 for channel 0 as an example. The
structure is identical for channels 1 to 15. The values in byte 0 and byte 1 are fixed and must
not be changed.
With an integration time of 2.5 ms, the measured value is changed by the following values
based on the additionally obtained basic error and noise:
• with "voltage", "current" and "resistance" by ±0.1 %
• with "Thermal resistor Pt 100 Standard" by ±0.4 K
• with "Thermal resistor Pt 100 Climatic" by ±0.3 K
• with "Thermal resistor Ni 100 Standard" by ±0.2 K
• with "Thermal resistor Ni 100 Climatic" by ±0.1 K
A detailed descrtion of the basic and operating error is available in the function manuaThe individual measured values are smoothed by filtering. The smoothing can be set in 4
levels for individual channels in STEP 7 (TIA Portal).
Smoothing time = Smoothing (k) x configured integration time
The following figure shows the time it takes for the smoothed analog value to reach
approximately 100% depending on the set smoothing. This is valid for all signal changes at
the analog input.None (smoothing = 1 x integration time)
② Weak (smoothing = 4 x integration time) *
③ Medium (smoothing = 16 x integration time) *
④ Strong (smoothing = 32 x integration time) *
* The smoothing time can increase by 1 x integration time.
Figure C-5 Smoothing time depending on the set smoothing level
The following table shows the time it takes for the smoothed analog value to reach
approximately 100% depending on the set smoothing and the set interference frequency
suppression.The cycle times (1 ms, 1.04 ms and 1.25 ms) result from the configured interference
frequency suppression. The cycle time is independent of the number of configured analog
channels. The values for the analog input channels are detected sequentially in each cycle.
Reference
For more information on conversion time, cycle time and conversion method, refer to the
Analog value processingEach analog value is entered left aligned into the tags. The bits marked with "x" are set to
"0".
Note
This resolution does not apply to temperature values. The digitalized temperature values are
the result of a conversion in the analog on-board I/O.The tables below set out the digitized representation of the input ranges separately for
bolar and unolar input ranges. The resolution is 16 bits.With suitable parameter assignment, events that occur trigger a diagnostics entry and a
diagnostics interrupt.
Table C- 15 Measured values for wire break diagnostics
Format Parameter assignment Measured values Explanation
S7 • "Wire break" diagnostics enabled
• "Overflow/Underflow" diagnostics
enabled or disabled
("Wire break" diagnostics has a higher
priority than "Overflow/Underflow" diagnostics)
32767 7FFFH "Wire break" or "Cable break" diagnostics
alarm
• "Wire break" diagnostics disabled
• "Overflow/Underflow" diagnostics
enabled
-32767 8000 H • Measured value after leaving the underrange
• Diagnostics alarm "Low limit" violated
• "Wire break" diagnostics disabled
• "Overflow/Underflow" diagnostics This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by personnel qualified for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of products
Note the following:
WARNING
products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by . Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
