GMBHR168 Datasheet, PDF (27/70 Pages) List of Unclassifed Manufacturers – Mini BLOCK Housing 16 opto inputs, 8 Relay outputs

ITALIAN TECHNOLOGY
Master
+
TX
-
+
RX
-
grifo^®
+ VCL -
R
R
Slave 1
5+
RX C.L.
6-
4+
CN6
3
TX C.L.
-
GMB HR168
Slave 2
5+
RX C.L.
6-
4+
CN6
3
TX C.L.
-
GMB HR168
Slave n
5+
RX C.L.
6-
CN6
4+
3
TX C.L.
-
GMB HR168
FIGURE 14: CURRENT LOOP NETWORK CONNECTION EXAMPLE
Possible Current Loop connections are two: 2 wires and 4 wires. These connections are shown in
figures 13÷15 where it is possible to see the voltage for VCL and the resistances for current limitation
(R). The supply voltage varies in compliance with the number of connected devices and voltage drop
on the connection cable.
The choice of the values for these components must be done cosidering that:
- circulation of a 20 mA current must be guaranteed;
- potential drop on each transmitter is about 2.35 V with a 20 mA current;
- potential drop on each receiver is about 2.52 V cwith a 20 mA current;
- in case of shortciruit each transmitter must dissipate at most 125 mW;
- in case of shortciruit each receiver must dissipate at most 90 mW.
For further info please refer to HEWLETT-PACKARD Data Book, (HCPL 4100 and 4200 devices).
GMB HR168 Rel. 5.00
Page 19