11-8
ET 200L, ET 200L-SC and ET 200L-SC IM-SC Distributed I/O Device
EWA 4NEB 780 6009-02c
11.5
Conversion and Cycle Times of the Analog Input Channels
In this section, you will find the definitions and interrelationships of the con-
version time and cycle time for analog input modules.
The conversion time consists of the basic conversion time and additional pro-
cessing times of the module. The basic conversion time depends directly on
the conversion process (integrated process, successive approximation) of the
analog input channel. In integrating conversion processes, the integration
time is included directly with the conversion time. The integration time is
dependent on the interface frequency suppression.
Analog/digital conversion and transfer of the digitized measured values to the
SC bus are sequential. In other words, the analog input channels are con-
verted one after the other. The cycle time (i.e. the time until another analog
input value is converted) is the sum of the conversion times of the activated
analog input channels of an analog input module (see Chapter 12). You
should activate unused analog input channels to reduce the cycle time.
The transfer of the digitized measured values to the system depends on the
interface used and the degree of expansion of the Smart Connect.
If you are using an ET 200L-SC with analog SC modules, you must allow the
following times for the transmission of the digitized measured values:
12 ms for each analog module
An additional 10 ms for each 2 AI TC SC module for which you have set
the reference temperature transfer parameter (dynamically or from the
dynamic reference temperature module on slot A)
The total cycle time thus depends on the cycle time in the SC modules (see
Chapter 12) plus the cycle times to the system, as described above.
Conversion time
Cycle Time in a
Module
Cycle Time to the
System
SC Analog Electronic Modules – Parameters
