Siemens CP 243-2 - Manual (Page 35)

Interface to the User Program in the S7-200 CPU
2-9
SIMATIC NET CP 243-2 AS-i Master
C79000-G8976-C142/02
2.3.2 Error Register in the Digital Module
Meaning for the User Program
This register always supplies the value ”0”. The CP 243–2 reports errors using the
error register in the analog module (see Section 2.4.2).
Example of Access to the Error Register
If the CP 243–2 is inserted directly beside the S7–200 CPU, SMB9 constantly
supplies the value ”0”.