Siemens SIMATIC S7-300 Module data Reference Manual

RS 485 Repeater
7-2
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
7.1 Application and Characteristics;
(6ES7972-0AA01-0XA0)
Order number
6ES7972-0AA01-0XA0
What is an RS 485 repeater?
The RS 485 repeater amplifies data signals on bus lines and interconnects bus
segments.
Application of the RS 485 repeater
You need an RS 485 repeater if:
• More than 32 nodes are connected to the bus
• Bus segments are to be operated non-grounded on the bus, or
• The maximum cable length of a segment is exceeded. (See table 7-1).
Table 7-1 Maximum Cable Length of a Segment
Baud Rate
Max. Cable Length of a Segment (in m)
9.6 to 187.5 kbd 1000
500 kbaud 400
1.5 Mbaud 200
3 to 12 Mbaud 100
Rules
If you configure the bus with RS 485 repeaters:
• Up to 9 RS 485 repeaters can be connected in series.
• The maximum cable length between two nodes must not exceed the values in
Table 7-2.
Table 7-2 Maximum Cable Length between Two RS 485 Repeaters
Baud Rate
Maximum Length of Cable between 2 Nodes (in m) with
RS 485 Repeater (6ES7972-0AA01-0XA0)
9.6 to 187.5 kbaud 10000
500 kbaud 4000
1.5 Mbaud 2000
3 to 12 Mbaud 1000

Siemens SIMATIC S7-300 Module data Specifications

General

Series	S7-300
Manufacturer	Siemens
Protection Class	IP20
System	SIMATIC S7-300
Digital Inputs	Varies by module
Digital Outputs	Varies by module
Analog Inputs	Varies by module
Analog Outputs	Varies by module
Central Processing Unit	Varies by CPU model
Supply Voltage	24V DC or 120/230V AC
CPU Type	Varies (e.g., CPU 312, CPU 315, etc.)
Memory	Varies by CPU model
Communication Interfaces	MPI, PROFIBUS
Programming Languages	LAD, FBD, STL, SCL, GRAPH
Operating Temperature	0°C to 60°C
Storage Temperature	-40°C to 70°C
Relative Humidity	10% to 95% (non-condensing)