39
Installing the serial communication cable for
RS485 SPA/IEC
Chapter 5
Installing the terminal
Figure 10:
Cable contact, Phoenix: MSTB2.5/6-ST-5.08 1757051
The EIA standard RS-485 specifies the RS485 network. An informative excerpt is given in
sec-
tion 5.2
5.2
Informative excerpt from EIA Standard RS-485
Informative excerpt from EIA Standard RS-485 - Electrical Characteristics of Generators and
Receivers for Balanced Digital Multipoint Systems
RS-485 Wire - Media dependent Physical layer
Where:
1
is cable
2
is screw
en03000110.vsd
1
2
1
Normative references
EIA Standard RS-485 - Electrical Characteristics of Generators and Receivers for Balanced Digital
Multipoint Systems
2
Transmission method
RS-485 differential bipolar signaling
2.1
Differential signal levels
Two differential signal levels are defined:
A+
=line A positive with respect to line B
A-
=line A negative with respect to line B
2.2
Galvanic isolation
The RS485 circuit shall be isolated from earth by:
Riso
≥
10 M
Ω
Ciso
≤
10 pF
Summary of Contents for REB 551-C3*2.5
Page 9: ...Contents ...
Page 21: ...12 Introduction to the installation and commissioning manual Chapter 1 Introduction ...
Page 27: ...18 Note signs Chapter 2 Safety information ...
Page 53: ...44 Installing the 56 64 kbit data communication cables Chapter 5 Installing the terminal ...
Page 59: ...50 Checking the binary I O circuits Chapter 6 Checking the external circuitry ...
Page 147: ...138 Repair support Chapter 16 Fault tracing and repair ...