Special Memory Byte Smb30; Smb31 And Smw32: Permanent Memory (Eeprom) Write Control - Siemens SIMATIC S7-200 System Manual

Table C-11 Special Memory Byte SMB30
Port 0
Format of
SMB30
SM30.6
and
SM30.7
SM30.5
SM30.2 to
SM30.4
SM30.0
and
SM30.1

SMB31 and SMW32: Permanent Memory (EEPROM) Write Control

You can save a value stored in V memory to permanent memory (EEPROM) under
the control of your program. To do this, load the address of the location to be
saved in SMW32. Then, load SMB31 with the command to save the value. Once
you have loaded the command to save the value, you do not change the value in V
memory until the CPU resets SM31.7, indicating that the save operation is
complete.
At the end of each scan, the CPU checks to see if a command to save a value to
permanent memory was issued. If the command was issued, the specified value is
saved to permanent memory.
S7-200 Programmable Controller System Manual
A5E00066097-02
Port 1
Format of
MSB
7
SMB130
p p d
SM130.6 pp: Parity select
and 00 =
SM130.7 01 =
10 =
11 =
SM130.5 d: Data bits per character
0 =
1 =
SM130.2 bbb: Freeport Baud rate
to 000 =
SM130.4 001 =
010 =
011 =
100 =
101 =
110 =
111 =
SM130.0 mm: Protocol selection
and 00 =
SM130.1 01 =
10 =
11 =
Note: When you select code mm = 10 (PPI master), the PLC will
become a master on the network and allow the NETR and
NETW instructions to be executed. Bits 2 through 7 are ignored
in PPI modes.
Special Memory (SM) Bits
Description
LSB
0
Freeport mode control byte
b b b m m
no parity
even parity
no parity
odd parity
8 bits per character
7 bits per character
38,400 baud
19,200 baud
9,600 baud
4,800 baud
2,400 baud
1,200 baud
600 baud
300 baud
Point-to-Point Interface protocol (PPI/slave mode)
Freeport protocol
PPI/master mode
Reserved (defaults to PPI/slave mode)
C-7