Communication
8.6 RS485
8.6.2
Baud rate and network address
8.6.2.1
Definition of baud rate and network address
Baud rate
The speed that data is transmitted across the network is the baud rate, which is typically
measured in units of kilobits (Kbps) or megabits (Mbps). The baud rate measures how much
data can be transmitted within a given amount of time. For example, a baud rate of
19.2 Kbps describes a transmission rate of 19,200 bits per second.
Every device that communicates over a given network must be configured to transmit data at
the same baud rate. Therefore, the fastest baud rate for the network is determined by the
slowest device connected to the network.
The following table lists the baud rates supported by the S7-200 SMART CPU.
Table 8- 14
Network
PPI protocol
Freeport Mode
Network address
The network address is a unique number that you assign to each device on the network. The
unique network address ensures that the data is transferred to or retrieved from the correct
device. The S7-200 SMART CPU supports network addresses from 0 to 126. The following
table lists the default (factory) settings for the S7-200 SMART devices.
Table 8- 15
S7-200 SMART device
STEP 7-Micro/WIN SMART
HMI
S7-200 SMART CPU
448
Baud rate supported by the S7-200 SMART CPU
Default addresses for S7-200 SMART devices
Baud rate
9.6 Kbps, 19.2 Kbps, and 187.5 Kbps only
1.2 Kbps to 115.2 Kbps
Default address
0
1
2
System Manual, V2.3, 07/2017, A5E03822230-AF
S7-200 SMART