Emerson Rosemount Smart Wireless THUM, Reference Manual

Page: 9 / 60

Reference Manual
00809-0100-4075, Rev BA
October 2010
1-3
Smart Wireless THUM Adapter
CONSIDERATIONS
General
The Smart Wireless THUM Adapter is connected to a HART sub-device. With
simple HART configuration, the THUM transmits the HART information from
the sub-device into the Wireless network.
Commissioning
The THUM can be commissioned before or after installation. It may be useful
to bench commission the THUM before installation to ensure proper operation
and to become familiar with the functionality. The instruments should be
installed in accordance with intrinsically safe or non-incendive field wiring
practices, when required. The THUM Adapter is powered when connected to
a powered loop.
Mechanical
When choosing an installation location and position for the transmitter, take
into account access to the device. For best performance, the antenna should
be vertical and have some space between objects in a parallel metal plane
such as a pipe or metal framework, as the pipes or framework may adversely
affect the performance of the antenna.
Electrical
The THUM Adapter is connected into a powered 4–20 mA loop, powering
itself by scavenging power. The THUM Adapter causes a voltage drop across
the loop. The drop is linear from 2.25 volts at 3.5 mA to 1.2 volts at 25 mA, but
does not effect the 4–20 mA signal on the loop. Under fault conditions, the
maximum voltage drop is 2.5 volts.
Environmental
Verify that the operating environment of the transmitter is consistent with the
appropriate hazardous locations certifications.
Temperature Limits
Wireless Considerations
Power Up Sequence
Power should not be applied to any wireless device until the Smart Wireless
Gateway (“Gateway”) is installed and functioning properly. Wireless devices
should also be powered up in order of proximity from the Gateway, beginning
with the closest. This will result in a simpler and faster network installation.
Enable Active Advertising on the Gateway to ensure that new devices join the
network faster. For more information see the Smart Wireless Gateway Manual
(Doc. No. 00809-0200-4420).
THUM Adapter Position
If possible, the THUM Adapter should be positioned vertically, either straight
up or straight down, and it should be approximately 3 ft. (1 m) from any large
structure, building, or conductive surface to allow for clear communication to
other devices. If the THUM Adapter is mounted horizontally, wireless
communication range may be decreased.
Operating Limit Storage Limit
–40 to 185 °F
–40 to 85 °C –40 to 185 °F
–40 to 85 °C