4.
The HART + pwr terminals when the
Trex Unit Power
is on and the Trex unit is
powering a positioner.
See
for more information.
4.5
Wiring diagrams for the Loop Diagnostics
application
CAUTION!
Remove the USB cable from the Trex unit before connecting to a device.
WARNING!
•
Do not connect lead sets to the HART and HART + pwr terminals at the same time. If the
lead sets are connected to devices, this increases the chance of wiring mistakes and
could create a short in the HART loop.
•
Do not add any external power to the device when the Trex unit is powering the device.
This can blow a fuse inside the Trex unit. The repair/replacement will need to be
completed at an authorized service center. Ensure the device is disconnected from the
loop/segment and no other wires are connected to the device before providing power
from the Trex unit.
•
The Trex unit cannot power a 4-wire device. Do not connect Trex unit to the power
terminals of a 4-wire device. This can blow a fuse inside the Trex unit. The repair/
replacement will need to be completed at an authorized service center.
•
Do not connect the mA terminals (ammeter) in parallel with a powered 4-20 mA current
loop. Ammeters have low resistance. This can disrupt the loop and cause devices to
report incorrect values or positioners to move unexpectedly.
•
Do not connect the mA terminals on the Trex unit to a power supply that is not current
limited to 250 mA. This can blow a fuse inside the Trex unit. The repair/replacement will
need to be completed at an authorized service center.
Loop Diagnostics application
130
User Guide
Summary of Contents for AMS Trex
Page 1: ...User Guide Rev 3 August 2017 AMS Trex Device Communicator User Guide ...
Page 8: ...Contents vi User Guide ...
Page 130: ...Field Communicator application 122 User Guide ...
Page 186: ...Fieldbus Diagnostics application 178 User Guide ...
Page 198: ...Technical specifications 190 User Guide ...
Page 206: ...Glossary 198 User Guide ...