Remove the USB cable from the Trex
unit before connecting to a device.
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
Power and connect to a FOUNDATION fieldbus device
To power a FOUNDATION fieldbus device, the Trex unit needs the
FOUNDATION fieldbus Power Plug. When the Trex unit powers a device, it also
provides two terminators and a power conditioner.
Warning: The Trex unit can power only one
FOUNDATION fieldbus device.
- FOUNDATION fieldbus Power
Connect to an externally-powered FOUNDATION fieldbus
For small fieldbus segments, the power conditioner and terminators
can be contained in a single wiring block.
Note: You can connect the Trex unit at any convenient place along the
fieldbus segment (bus). In the field, this is typically done at the device or
at the fieldbus junction box. The drawing below is one example.
- Power conditioner
- Fieldbus power supply
- Host system