Siemens SIMATIC ET 200AL, System Manual

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What you should know about analog technology
2.18 Settling and response times of analog output modules
Analog value processing
52
Function Manual, 06/2014, A5E03461439-AC
2.18 Settling and response times of analog output modules
Settling and response times provide information on the delay of the output of a specified
analog output variable and its availability to the process.
Response time
The response time for a new output value is defined as the time between the input of a
digital output value to the internal memory of the module and the value to be output at the
analog output being reached (with a residual error of 1 %).
The response time (t
A
) is the sum of application time (t
X
), conversion time (t
W
) and settling
time (t
E
):
t
A
= t
X
+ t
W
+ t
E
Settling and response times of analog output modules
t
A
Response time
t
X
Application time
t
Z
Module cycle time
t
W
Conversion time
t
E
Settling time
t
1
New digital output value is available in the internal memory of the module
t
2
Module activates the digital output value and starts conversion
t
3
Module ends conversion at the terminal of the analog output channel and outputs the analog
signal
t
4
Signal has settled and the specified analog output value has been reached (residual error 1 %)
Figure 2-22 Settling and response time of an output channel