Precautions For Using The Trex Unit With Foundation Fieldbus Devices; Foundation Fieldbus Communication Terminals - Emerson AMS Trex User Manual

Field Communicator application
3.18.1 Precautions for using the Trex unit with FOUNDATION
fieldbus devices
WARNING!
If a fieldbus segment is connected to a host system, the changes made with the Trex unit may
not be recorded in the host system's permanent database. Verify the changes in the database.
Otherwise, this could cause unpredictable results and, depending upon your application,
process disruption leading to property damage, serious injury, or death. Ensure all safety
precautions and work procedures have been followed.
WARNING!
Changing device parameters could adversely affect the control of your process. Put the control
loop in Manual/Out of Service before applying changes. Verify the output before returning the
control loop to Auto. Failure to do so could result in property damage, serious injury, or death.
Ensure all safety precautions and work procedures have been followed.
CAUTION!
The Trex unit draws approximately 12 mA from the fieldbus segment when it is online. (The
Trex unit draws 0 mA when it is offline.) Ensure the power supply or barrier on the fieldbus
segment has the capacity to provide this additional current when the Trex unit is online. If a
heavily loaded fieldbus segment is drawing near the capacity of the segment's power supply,
connecting the Trex unit may result in loss of communication.
3.18.2

FOUNDATION fieldbus communication terminals

The Trex unit has terminals that enable communication with FOUNDATION fieldbus
devices. Insert the lead set into the FF terminals and connect to a FOUNDATION fieldbus
device or to a connection point on the fieldbus segment.
On the Device Communicator Plus communication module, the red FF pwr terminal
enables the Trex unit to power one FOUNDATION fieldbus device. To use this terminal, you
need the FOUNDATION fieldbus Power Plug that connects to the FF pwr terminal and the
positive (red) FF terminal. This lets the Trex unit communicate with and power one
FOUNDATION fieldbus device.
96 User Guide