Emerson 375 User Manual page 66

4-6 Fieldbus Functionality
There are three terminals on the top of the 375 Field
Communicator. Two are red and one is black. Each red
terminal is a positive connection for its protocol. The
black terminal is a common terminal shared by both
protocols. An access door ensures only one pair of
terminals is exposed at any one time; see Figure 4-2.
Several markings indicate which pair of terminals is for
which protocol.
Figure 4-2. Fieldbus terminal access door
Fieldbus Terminal Markings