Example for MODBUS connection
MODBUS
26.02.2007
v_modbus_verbindung.vsd
The data line must be conducted from one device
to the next. No other type of wiring is allowed!
Always use only two wires of one lead (twisted
pair) for the connection.
Recommended wire types
1. CAT5 / CAT7 cables
2. J-Y (St) 2x2x0.6 (telephone cable)
3. AWG22 (2x2 twisted pair)
Max allowed wire length 1000 m (CAT5/7 500 m).
Shielding
The use of shielded cables is normally not needed but offers high protection against
electromagnetic interferences, especially high frequencies. However, the effectiveness
of the shield depends on careful installation of the line.
If shielded cables are used, the shield should be placed at
“
PE
”
on at least one side
(preferably on the master connection). The occurrence of compensating currents may
have to be considered if the shield is contacted on both sides.
Shield connection correct
Shield connection incorrect
When using telephone cable with four cable cores, we recommend the following
allocation:
•
A (D+) = red
•
B (D-) = black
•
ID1 - ID2 = yellow (for automatic addressing)
•
GND = white
Operating Instructions
UNIcon
CTG-150AVC
Electrical installation
L-BAL-E287-GB 2015 Index 004
Part.-No.
10/36