KEYENCE LK-G Series - Manual (Page 8)

6 LK-G-M-NO0-E
LK-G3001PV/LK-G3001P (PNP type)
Precautions when connecting to computers or other external devices
When working in a positive grounding environment, when the LK-G is connected to a
computer through USB in order to use LK-Navigator or when establishing RS-232C
communication with a computer, take precautions to avoid shorts in between the SG
(GND) terminals for the computer and the LK-G.
24 VDC (-), SG (GND) of USB, and SG (GND) of RS-232C are all common via a choke coil.
Make sure that a voltage potential difference does not occur with external devices such as
computers or PLC. If a voltage potential difference occurs, use with insulation on the LK-G
power supply and the I/O terminals other than RS-232C and USB.
LK-G3001P(V) LK-G3001P(V)
COM OUT
COM IN
DC24V(+)
DC24V(-)
DC24V
COM OUT
COM IN
DC24V(+)
DC24V(-)
DC24V
The power supply (24 VDC) shorts via the
COM terminals, causing malfunctions.
GND GND
➀ ➁ The power supply (24 VDC) shorts via
the SG (GND) terminals for LK-G and
the computer, causing malfunctions.
Insulate the computer (
➀ in the figure)
and LK-G ( ➁ in the figure).
* The internal wiring in the computer,
PLC, or other device differs
depending on the device. For details,
refer to the instruction manual for each
device.
LK-G3001P(V) Computer
GND
termin
al
GND
RS-232C/
USB GND
DC24V(+)
DC24V(-)
DC24V
RS-232/
USB GND RS-232C/
USB cable
LK-G-M-NO0-E.fm 6 ページ ２００７年９月５日 水曜日 午後８時３５分