30
UMG 508
Shields
A twisted, shielded cable is foreseen for con-
nections using the RS485 interface.
• Ground the shields of all cables leading to the
cabinet at the cabinet entry point.
• Connect the shield extensively and with
good conductivity with a low external voltage
ground.
• Intercept the cable mechanically above
the ground clip in order to avoid damages
caused by cable movements.
• Use suitable cable insert guides, such as PG
glands, to guide the cable into the switch ca-
binet.
Cable type
The cables used must be suitable for an envi-
ronmental temperature of at least 80°C.
Recommended cable types:
Unitronic Li2YCY(TP) 2x2x0.22 (Lapp cable)
Unitronic BUS L2/FIP 1x2x0.64 (Lapp cable)
Maximum cable length
1200m at a Baud rate of 38.4k.
Illu. Shielding arrangement at cabinet entry
point.
Cable
Strain relief
Cable shielding braid.
Grounding clip
Low external voltage
ground.
Terminal resistors
The cable is terminated with resistors (120Ohm
1/4W) at the beginning and end of a segment.
The UMG508 does not have any terminal resis-
tors.
C
For the wiring of the Modbus con-
nection, CAT cables are not suitable.
Please use the recommended cables.