Program instructions
7.3 Communication
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
201
You can only use Freeport communications when the CPU is in RUN mode. Enable the
Freeport mode by setting a value of 01 in the protocol select field of SMB30 (Port 0) or
SMB130 (Port 1). While in Freeport mode, you cannot communicate with an HMI on the
same port.
Note
The serial CR model CPUs disable Freeport mode when you connect a USB-PPI cable to
the CPU. Likewise, the CPU inhibits the switch to Freeport mode if you connect a USB-PPI
cable to the CRs CPUs.
Changing PPI communications to Freeport mode
SMB30 and SMB130 configure the communications ports, 0 and 1 respectively, for Freeport
operation and provide selection of baud rate, parity, and number of data bits. The following
figure describes the Freeport control byte. One stop bit is generated for all configurations.
pp
Parity select
d
Data bits per character
00 =
01 =
10 =
11 =
No parity
Even parity
No parity
Odd parity
0 =
1 =
8 bits per character
7 bits per character
bbb
Freeport baud rate
mm
Protocol selection
000 =
001 =
010 =
011 =
100 =
101 =
110 =
111 =
38400
19200
9600
4800
2400
1200
115200
57600
00 =
01 =
10 =
11 =
PPI slave mode
Freeport mode
Reserved (defaults to PPI slave mode)
Reserved (defaults to PPI slave mode)