3-7 Installing the Video Input Unit
3-43
Grounding Precaution
Either ground the Camera, PT, and PLC at only one point, or connect the grounds for each with a spe-
cial line. Some computers internally connect the SG terminal to the RS-232C and USB connector hoods.
If such a computer is connected to the PT or PLC and there is a ground potential difference between the
Camera and the PT/PLC, an overcurrent may flow through the electronic components inside the NS-
CA001 or NS-CA002 as shown in the following figure, possibly damaging the NS-CA001 or NS-CA002.
Recommended Connections
Ground to only one point as shown in the following figure or use equivalent wiring so that there is no dif-
ference in ground potential.
Camera
PLC
Computer
NS-CA001
NS-CA002
PT
Electronic
component
Difference
in potential
Functional
ground
SG
Case
SG
Video Cable
LG
GR
SGSG
RS-232C cable
RS-232C
connector hood
RS-232C
connector hood
SGSG
RS-232C cable
*The example in the above figure shows a computer connected to an RS-232C
connector on the PLC.
Camera
PLC
Computer
NS-CA001
NS-CA002
PT
Electronic
component
Functional
ground
SG
Case
SG
Video Cable
LG
GR
SGSG
RS-232C cable
RS-232C
connector hood
RS-232C
connector hood
SGSG
RS-232C cable
To Next Page
Loading...
