Siemens SIMATIC ET 200eco PN, Руководство по эксплуатации

Страница: 258 / 278

Response times for analog input device and output
device
F
F.1 Response times for analog input device
Conversion time
The basic conversion time depends directly on the conversion method of the analog input
channel (integrating method, instantaneous value conversion). For the integrating
conversion method, the integration time is included directly in the conversion time. The
integration time depends on the interference frequency suppression.
For information on the basic conversion times and additional processing times of the
individual analog devices, refer to the technical data of the corresponding analog I/O device.
Cycle time
The analog-digital conversion and the transfer of the digitized measured values to memory or
to the backplane bus take place sequentially. In other words, the analog input channels are
converted one after the other. The cycle time, that is, the time until an analog input value is
converted again, is the sum of the conversion times of all the activated analog input channels
of the analog input devices. You should deactivate unused analog input channels during
parameter assignment in order to reduce the cycle time. The conversion and integration time
for a deactivated channel is 0.
The figure below provides an overview of the cycle time elements of an n-channel analog
input device.
&RQYHUVLRQWLPHFKDQQHO
&RQYHUVLRQWLPHFKDQQHO
&\FOHWLPH
&RQYHUVLRQWLPHFKDQQHO
Q
Figure F-1 Cycle time for analog input devices
Settling time
See Smoothing .
259
ET 200eco PN
Operating Instructions, 06/2022, A5E01250250-AN