Siemens SIPROTEC 4 User Manual page 21

The analog input quantities are passed on to the input amplifiers (IA). The input amplifier IA element provides
a high-resistance termination for the input quantities. It consists of filters that are optimized for measured-
value processing with regard to bandwidth and processing speed.
The analog-to-digital (AD) element consists of a multiplexor, an analog-to-digital (A/D) converter and of
memory components for the transmission of digital signals to the microcomputer system.
[hw-struktur-7sj64-110602-kn, 1, en_US]
Figure 1-2
Microcomputer System
Apart from processing the measured values, the microcomputer system (μC) also executes the actual protec-
tion and control functions. They especially include:
•
Filtering and preparation of the measured quantities
•
Continuous monitoring of the measured quantities
•
Monitoring of the pickup conditions for the individual protective functions
•
Interrogation of limit values and sequences in time
•
Control of signals for the logic functions
•
Output of control commands for switching devices
•
Recording of messages, fault data and fault values for analysis
SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016
Hardware structure of the digital multifunctional protection devices 7SJ623, 7SJ624, 7SJ625,
7SJ626 and 7SJ62/64
Introduction
1.1 Overall Operation
21