Siemens SIMATIC S7 System Manual page 467

Table 8- 22 Using Freeport mode
Network configuration
Using Freeport over an
RS232 connection
Using USS protocol
Creating a user program
that emulates a slave
device on another net-
work
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
Description
Example: Using an S7-200 SMART CPU with an
electronic scale that has an RS232 port.
Connect the two devices using one of the follow-
•
ing methods:
– RS232/PPI Multi-Master cable connects the
RS232 port on the scale to the RS485 port
on the CPU. (Set the cable to PPI/Freeport
mode, switch 5 = 0.)
– Using the CM01 signal board (SB) (S CPUs
only) which supports RS232 and RS485, you
can connect the RS232 device directly to the
CPU SB RS232 without using the RS232/PPI
cable.
CPU uses Freeport to communicate with the
•
scale.
Baud rate can be from 1.200 Kbps to
•
115.2 Kbps.
User program defines the protocol.
•
Example: Using an S7-200 SMART CPU with
SIMODRIVE MicroMaster drives.
STEP 7-Micro/WIN SMART provides a USS
•
library.
The CPU is a master, and the drives are slaves.
•
Example: Connecting S7-200 SMART CPUs to a
Modbus network.
User program in the CPU emulates a Modbus
•
slave.
STEP 7-Micro/WIN SMART provides a Modbus
•
library.
Communication
8.6 RS485
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