IAI America RCM-GW-DV - Manual (Page 23)

DeviceNet Gateway
b. Notes on wiring method
Separate the communication lines of the Gateway Unit and Profibus module from lines carrying
large current such as power circuits. (Do not bundle them together or place them in the same
cable duct.)
c.
Noise sources and elimination of noise
There are many noise sources, but the ones you should pay most attention to when building
your system are solenoid valves, magnet switches and relays. Noise from these sources can be
eliminated using the following measures.
[1] AC solenoid valves, magnet switches, relays
Measure --- Install a surge killer in parallel with the coil.
[2] DC solenoid valves, magnet switches, relays
Measure --- Install a diode in parallel with the coil. Determine an appropriate diode capacity
in accordance with the load capacity.
← Point
Install the surge killer in a location as close as
possible to each coil.
If the surge killer is installed on a terminal block
or away from the coil, its noise elimination
effect will decrease.
In a DC system, connecting the diode in reverse polarities may
damage the diode, internal controller parts, and DC power supply.
Exercise due caution.
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