Smw22 To Smw26: Scan Times; Special Memory Words Smw22 To Smw26; Smb28 And Smb29: Analog Adjustment; Smb30 And Smb130: Freeport Control Registers - Siemens SIMATIC S7-200 System Manual

Special Memory (SM) Bits

SMW22 to SMW26: Scan Times

As described in Table C-9, SMW22, SMW24, and SMW26 provide scan time
information: minimum scan time, maximum scan time, and last scan time in
milliseconds.
Table C-9

Special Memory Words SMW22 to SMW26

SM Word
SMW22
SMW24
SMW26

SMB28 and SMB29: Analog Adjustment

As described in Table C-10, SMB28 holds the digital value that represents the
position of analog adjustment 0. SMB29 holds the digital value that represents the
position of analog adjustment 1.
Table C-10 Special Memory Bytes SMB28 and SMB29
SM Byte
SMB28
SMB29

SMB30 and SMB130: Freeport Control Registers

SMB30 controls the Freeport communication for port 0; SMB130 controls the
Freeport communication for port 1. You can read and write to SMB30 and
SMB130. As described in Table C-11, these bytes configure the respective
communication port for Freeport operation and provide selection of either Freeport
or system protocol support.
C-6
Description (Read Only)
This word provides the scan time of the last scan cycle.
This word provides the minimum scan time recorded since entering the RUN
mode.
This word provides the maximum scan time recorded since entering the
RUN mode.
Description (Read Only)
This byte stores the value entered with analog adjustment 0. This value is
updated once per scan in STOP/RUN.
This byte stores the value entered with analog adjustment 1. This value is
updated once per scan in STOP/RUN.
S7-200 Programmable Controller System Manual
A5E00066097-02