ABB RER 133 Teknik Açıklama - Sayfa 12
Kontrol Ünitesi ABB RER 133 için çevrimiçi göz atın veya pdf Teknik Açıklama indirin. ABB RER 133 16 sayfaları. Bus connection module
Sayfayı Yazdır
Bus Connection
Module
12
RER 133
Technical Description
The EIA RS-485 Specification labels the data wires "A" and "B", but many
manufacturers label their wires "+" and "-". In our experience, the "+" wire should
be connected to the "A" line, and the "-" wire to the "B" line.
When wiring RS-485 , use a shielded twisted pair cable with an internal impedance
Ω
of 100-120
. Examples of recommended cables are CAT 5, Belden RS-485 (9841-
9844) and Alpha Wire (Alpha 6222-6230).
The shield of the cables must be directly connected to ground in one
of the nodes. In the other nodes the connection should be made via a
capacitor, i.e. if the shield of the cable is connected to pin 1 in node
1, all the other nodes must be grounded using pin 2.
1
2
3
4
5
6
7
8
Fig. 6.-3 Example on a cable shield connection
1
2
3
4
5
6
7
8
1MRS755163
1
2
3
4
5
6
7
8
A050325