Networking terminals with cam controls and PCs
Deutschmann Automation GmbH & Co. KG
16
Instruction manual LOCON 7, LOCON 9 V. 10.4
24.5.04
The minimum wiring with shielding between two bus users is shown in the following illustration:
Picture 2: DICNET-wiring
The two signal wires may not be reversed!
GND of the two devices do not necessarily have to be connected.
The potential difference between the data reference potentials GND of all
interface connections may not exceed ± 7 V.
4.3.1
Earthing, shielding
If using a shielded bus cable, we recommend that the shield is connected at both ends and with
low inductance with the protective ground in order to achieve optimum EMC wherever possible.
4.3.2
Line termination at
DICNET
®
The two ends of the entire bus cable must each be fitted with a line termination. This avoids sig-
nal reflections on the line and ensures a defined open-circuit potential if no user is transmitting
(state of rest between the telegrams, so-called idle state).
In this case, please ensure that the line termination is made at the physical ends of the bus
cable, i. e. the integrated bus termination resistor must be activated at both devices located at
the start and end of the bus.
4.4
Comparison DICNET
®
- RS232
If you intend to set up a permanent link between terminal and one or more cam controls, prefer-
ence should be given to connection via the DICNET bus and not the RS232 interface since the
bus features a higher level of data integrity, i. e. transmission errors which may occur, for
instance, as the result of noise pulses are automatically detected and corrected by DICNET up to
a certain extent.
Wherever possible, the RS232 interface should be used only for temporary connections (e. g. for
connecting a PC).