The first thing you need to know about powering up a HART device with an AMS Trex communicator is that the latter is a modular device. At the present time, you have two module options to choose from.
AMS Trex Modules
The first module is relatively basic. With the basic module, you can read the HART and FOUNDATION Fieldbus devices. Unfortunately, that’s it! If you are not allowed to provide power to the field device, then you need to have all the accessories necessary to power up the transmitter.
The second module provides you with a few more possibilities. Just like the basic module, you can read the information from the HART and FOUNDATION Fieldbus devices. Equally important, you can power up both types of devices. Last but not least, you can read milliamperes from a device output.
To conclude, the user experience is an outstanding part of this field communicator. If you don’t know exactly how to do a task, the device gives you step by step instructions on the screen.
Powering up a HART device
Okay, if you need to power up the device the procedure is really simple. First, you need to connect the cable in the HART+pwr input in the AMS Trex. In this situation, you don’t need to worry if you connect incorrectly or in the wrong port. The device can actually detect voltage and avoid a problem in the loop communicator. In this case, it can even detect an incorrect connection. As soon as you connect the cable in the AMS Trex and your field device, click on field communicator on Trex’s screen.
The device will detect if you have power or not. If you don’t have power you can select the option ‘power up’ in the field device. All this information should pop up on the screen. Another key point, with HART communication, you don’t need to have an external resistor. The AMS Trex already has one inside! When you power up the device, the Trex will read the HART information and display the process values with set up options for you.
Below you have a video showing the step by step how to power up a field device: