24.5.04
Instruction manual LOCON 7, LOCON 9 V. 10.4
15
Deutschmann Automation GmbH & Co. KG
Networking terminals with cam controls and PCs
4
Networking terminals with cam controls and PCs
The chapters below illustrate certain connection examples between the units and a PC, via the
DICNET bus as well as via the RS232 interface.
All DEUTSCHMANN controls (LOCON, ROTARNOCK ...) with a DICNET bus can be included in
this network. The following principles apply in general:
4.1
RS232 link
An RS232 link is always a point-to-point link for 2 users.
Here, it must be borne in mind that, on connection, the Tx end of one user is connected to the Rx
end of the other user and vice versa. Moreover, the device ground potentials must be intercon-
nected.
4.2
RS485-connection (DICNET
®
) - LOCON 9 only
A DICNET link is a bus system to which at maximum configuration level 16 cam controls
(LOCON 32, LOCON 9 ...), 16 display units (TERM 4), 3 operating terminals (TERM 6, TERM 24
...) and 1 PC can be connected simultaneously via a twisted two-wire line which should be
shielded.
All "“ ports are interconnected and all "DICNET-" ports are interconnected. A wiring as
on the RS232 interface is not made.
Likewise, a connection of the individual device ground potentials as on the RS232 interface has
not necessarily to be made; however, you must ensure that the potential difference between
the individual devices does not exceed 7 V.
Consequently, equipotential bonding is generally carried out in practice at a central point (for
example, in the switch cabinet).
Moreover, please ensure that the two bus users feature bus termination resistors at the
start and end of the bus by connecting to R+ and DICNET- to R-, since, otherwise,
serious transmission problems could occur.
If the devices are connected to the bus with a stub-end feeder, the length of the stub-end feeder
may not exceed 1 m, so as to guarantee trouble-free operation.
By default LOCON 9 is supplied with activated bus termination resistor.
4.3
Cable type for DICNET
®
A shielded, twisted, 2-core cable (twisted pair) is recommended to be used as bus cable. The
shield serves to enhance electromagnetic compatibility (EMC). However, an unshielded cable
may also be used if ambient conditions permit it, i. e. if no electromagnetic interference (EMI) is
to be expected.
The characteristic impedance of the cable should be between 100 and 130 *
Ω
at f > 100 kHz; the
cable capacitance should be < 60 pF/m wherever possible and the wire cross-section should be
minimum 0.22 mm
2
(24 AWG).
A cable that fully complies with these specifications and that has been developed specifically for
use in field bus systems is the UNITRONIC®-BUS LD cable 2 x 2 x 0.22, available on a drum
from LAPP KABEL in Stuttgart, or by the meter from Deutschmann Automation.