BeiJer X2 base 7 User Manual

Additional Installation Tip s
6.6 GalvanicIsolation
USB
USB
RS232RS422/485
+24 V DC
0 V
Filter
DC/DC
galvanic isolation
VCC
0 V (GND)
DC/AC
CFL
Ethernet
Internal electronics
1.5 m
The operator panel has galvanic isolation against the 24 V DC feed but no galvanic
isolation between the communication ports for RS232, RS422/485 and USB.
Only the Ethernet connection has galvanic isolation.
* *
*
***
**
*
Operator panel Modular controller Printe
r
PCPC
Different ground potential
*
= Internal 0 V (GND) connection
Power CPU COM COM2
RS422 RS232 USB
When a PC is connected to the operator panel, the internal 0 V (GND) of the
panel is connected to the protective ground via the PC.
A number of USB devices can have the shield connected together with the
protective ground. Here, the 0 V (GND) of the operator panel is connected to the
protective ground when, for example, a USB memor y stick, keyboard, or s imilar
device is plugged in.
If a number of units are con nected that have a 0 V and a ground connection, and
these are connected to various grounding points, there is a substantial risk of
problems. Grounding currents go through communication cables, the rear plate
of the controller, and internally in the operator panel, and can cause errors.
Use external un its to improve communication and achieve galvanic isolation.
Westermo has good industry-standard insulators that are also insulated from the
24 V DC feed.
Note:
Itisveryimportanttomakesuret hatthe24Vfeedintheexternalinsulationunitisnot
connectedtooneofthecommunicationoutlets. Ifitdoesnothave100%insulation
againstthe24Vfeed,disturbancesandgroundingcurrentsfromthe0Vonthe24V
sidedisruptsthecommunication.
Usingthistypeofunitsolvesoneproblembutcreatesalargerproblem! Asubstandard
installationmayworknow,butproblemsmayarisewhenotherdevicesareconnected.
BeijerElectronics, MAEN181B
24

BeiJer X2 base 7 Specifications

General

Brand	BeiJer
Model	X2 base 7
Category	Touch Panel
Language	English