Honeywell CADVR-04D User Manual page 231

circuit is just grounded only and they are connected at the same port.
Since there is only one common port, there is no circuit and so, there is
no interference.
Multiple-point ground: In the following figure, you can see the internal
circuit uses the chassis as the common point. While at the same time,
all devices chassis use the earthing as the common port. In this
connection, the ground structure can provide the lower ground
resistance because when there are multiple-point grounds; each ground
cable is as short as possible. And the parallel cable connection can
reduce the total conductance of the ground conductor. In the high-
frequency circuit, you need to use the multiple-point ground mode and
each cable needs to connect to the ground. The length shall be less
than the 1/20 of the signal wavelength.
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