For Output Connection; Rs485 Communication - Panasonic KW8M User Manual

Operating power supply
Measured voltage input
Do not ground the secondary side.

3.4 For Output connection

・Since the transistor output is insulated from the internal circuit by a photo-coupler, it can be used both
as a NPN output and PNP (equal value) output.
NPN output Pulse (+)

3.5 RS485 Communication

・When using shielded cable for the RS485 transmission line, ground one end.
Use a class D dedicated earth for grounding. Do not share a ground with other earth lines. (Fig.1)
・Be sure to connect with daisy chain the RS485 transmission line between each unit.
Do not use a splitter. (Fig.2)
・With a terminal station, RS485 (E) (No.10) and RS485 (-) (No.9) should be shorted.
*E terminal is not SG (signal ground) terminal. Do not ground shielded cable.
(Fig.1)
To RS485 device
(Fig.2)
(Fig.B) No Good example
Insulated
Input equipment
transformer
(sensor etc.)
(＋)
(－)
Eco-POWER
METER
Eco-POWER METER
Pulse (－)
6 7
Load
+ -
Power supply for Load
Eco-POWER METER
Shielded cable
Class D grounding
Correct wiring
○
Incorrect wiring
×
Operating power supply
Measured voltage input
Auto transformer
Eco-POWER
Do not use an auto-transformer.
PNP output Pulse (+)
General station
(＋) (－) ( E )
Shielded cable
Terminal
station
10
KW8M Eco-POWER METER
Input equipment
(sensor etc.)
(＋)
(－)
METER
Eco-POWER METER
Pulse (－)
6 7
Load
+ -
Power supply for Load
Eco-POWER METER
Terminal station
(＋) (－) ( E )
Shorted
Class D grounding
Terminal
station