Revision 1 – 04.12.2015
9/28
CONNECTION SERIAL NET RS485
To connect a serial net you have to pay carefully attention to some executive aspects:
1)
Use flexible cable, shielded, twisted 22 AWG type.
2)
Connect D- and D+ to two conductors of same couple and 0 to a third one (if available) or both conductors of a
second couple.
3)
Connect the cable’s shield to only one end of 0.
4)
DO NOT CONNECT the cable’s shield to the electrical ground of the plant.
5)
The net MUST NOT BE LONGER than 400 meters.
6)
Max connectable units through serial net RS 485 is 32.
7)
In case of connection via serial line RS485 you have to set the parameter
C08
into menu
04
Compressor setup:
this is the number you need to combine to the recognition of the controller.
8)
The units on serial net RS485 must be connected without any reversal: pole D+ to D+, pole D- to D-, pole 0 to 0.
9)
In case of connection with more than 2 units it is necessary to provide only one line without any deriving.
At the terminal both starting and ending the net it is possible to place (in parallel to D- and D+) a termination
resistance 120 Ohm.
In the picture below you can see the connection of 4 units on serial net RS485 by using a shielded cable with two
twisted couples.
NOTES ON THE WIRING: wrong wiring can damage both the controller and other devices connected to the
serial port.
WARNINGS TO THE WIRING RS485
1)
The cable must be placed into a TRUNK SEPARATED by power cables and any potentially dangerous cables as
lighting plant and so on.
2)
DO NOT PLACE signal cables next to power bar, lighting lamps, antennas, transformers;
3)
Keep signal cables FAR 2 METERS MINIMUM from units with heavy inductive (distribution cabinet, motors,
inverter).
4)
Don’t pull the cables with a strength over 12 Kg; stronger strength can damage the wires and reduce the signal
transmission on the line.
5)
DO NOT: twist, knot, crush or fray the conductors.
6)
Do not make any joints between lengths of cable: always use only one cable to connect any single unit to each
others. Strip the end part carefully, do not crush the cable next to core-hitches or safety supports.
7)
Always respect the position of the colors at the both sides of the connection.
Once the wiring is complete, visually and physically check the cables are undamaged and properly placed
