Siemens SIMATIC User Manual

Analog modules
6.9 Analog input module SM 331; AI 8 x RTD; (6ES7331-7PF01-0AB0)
S7-300 Module data
Manual, 06/2017, A5E00105505-AJ
391
6.9.4 Additional information on SM 331; AI 8 x RTD
Modes of operation
Operating modes of SM 331; AI 8 x RTD:
● 8-channel mode (hardware filter)
● 8-channel mode (software filter)
● 4-channel mode (hardware filter)
The operating mode influences the module cycle time.
8-channel mode (hardware filter)
In this mode, the module changes between the two channels of each group. The four ADCs
of the module simultaneously convert channels 0, 2, 4 and 6. The ADCs first convert the
channels with even numbers, and then the channels with the odd numbers 1, 3, 5 and 7 (see
the figure below.)
Figure 6-23 8-channel mode cycle time (hardware filter)

Siemens SIMATIC Specifications

General

Brand	Siemens
Model	SIMATIC
Category	Control Unit
Language	English