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© Sealevel Systems, Inc. 7106e Manual | SL9268 11/2022
Appendix E – Ground loop Phenomenon
What is Ground Loop?
Ground loop Phenomenon occurs when two (or more) pieces of equipment are connected together with a
common ground and a different ground potential exists at each location. This current can cause the
connected equipment to experience noise that in turn causes data transmission errors. In the extreme this
ground current can cause equipment malfunction or even destruction.
Cabling Recommendations
When connecting the 7106e in a RS-485 network, care should be taken that both ends of the network are
not isolated from ground (see Figure 8). This “floating” ground condition could cause the capacitive or
inductive coupling of voltages that will cause a break down in the DC to DC converter circuit or in the opto-
isolator circuit. This condition will cause data errors and possibly destruction of the receiver circuit
.
A
B
Isolation
Barrier
DATA+
DATA-
Ground
Isolated
Adapter
Non
Isolated
Adapter
