Technical data

RS 485 Repeater
Manual, 02/2011, A5E03382072-01
9
Description
3
3.1 Area of application and properties
Order number
6ES7972-0AA02-0XA0
What is the RS 485 repeater?
The RS 485 repeater amplifies data signals (amplitude, edge slope and signal width) on bus
lines and couples segments.
Application of the RS 485 Repeater
The RS 485 repeater connects two PROFIBUS or MPI segments using RS 485 technology
with maximum 32 nodes. It enables transfer rates from 9.6 kbps to 12 Mbps.
You need an RS 485 repeater if:
● More than 32 nodes (maximum 127, including repeaters) are connected to the bus
● Segments are operated ungrounded on the bus (electrical isolation of segments)
● The maximum cable length of a bus segment is exceeded (see the table below)
● Help is required during the commissioning
– Switch for disconnecting segments
– Display of bus activity
– Disconnecting a bus segment in the case of incorrectly inserted terminating resistors
● The signals are to be regenerated in amplitude and time
Table 3- 1 Maximum cable length of a bus segment
Transmission rate Max. cable length of a bus segment (in m)
9.6 to 187.5 kbps 1000
500 kbps 400
1.5 Mbps 200
3 to 12 Mbps 100