Siemens ET 200S - Page 546

Response Times
D-8
Distributed I/O System ET 200S
EWA 4NEB 780 6024-02 07
Response Time
The response time (t
1
to t
3
) – that is, the time from the application of the digital
output values in internal memory until the specified value is obtained at the analog
output – is, in the most unfavorable case, the sum of the cycle time and the settling
time. The most unfavorable case is when the analog channel is converted shortly
before the transfer of a new output value and is not converted again until after the
conversion of the other channels (cycle time).
Figure D-7 shows the response time of an analog output channel.
t
A
t
Z
t
E
t
1
t
2
t
A
= response time
t
Z
= cycle time, corresponding to the processing time of the module
and the conversion time of the channel
t
E
= settling time
t
1
= new digital value applied
t
2
= output value transferred and converted
t
3
= specified output value obtained
t
3
Figure D-7 Response Time of an Analog Output Channel
D.7 Response Times for a 4 IQ-SENSE Electronic Module
The response time of the 4 IQ-SENSE electronic module is specified as a cycle
time in the technical specifications.
D.8 Response Times for Process-Related Modules
The response times of the process-related modules are indicated as response time
or update rate in the technical specifications. See the ET 200S Process-Related
Functions manual