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3 meaning of the data in the digital module – Siemens CP 243-2 User Manual

Page 33

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Interface to the User Program in the S7-200 CPU

2-7

SIMATIC NET CP 243-2 AS-i Master
C79000-G8976-C142/02

2.3

Meaning of the Data in the Digital Module

Overview

The digital module of the CP 243-2 consists of four registers:

S

Identification register, 8 bits (I/O module identifier)

S

Error register, 8 bits

S

Input register 8DI (status byte of the CP 243-2)

S

Output register 8DO (control byte of the CP 243-2)

Essentially, the functions shown in the following diagram are handled via these
registers:

CP 243-2

User program

Digital module (8DI/8DO)

Analog module (8AI/8AO)

S7-200 CPU

НН

НН

НН

НН

НН

НН

ОО

ОО

ОО

ОО

ОО

ОО

AS-i master

AS-i cable

S

Status/error information

S

Control of the CP

S

Bank selection

Figure 2-2