Emerson DL8000 - Page 69

DL8000 Preset Instruction Manual
Revised February-2016 Modules 3-31
A DL8000 equipped with a HART-2 module is considered to be a
HART Host (primary master) interface with a Class 1 Conformance
classification. The HART-2 module can also be configured with
ROCLINK 800 Configuration software for use as a secondary master in
redundant applications.
Most Universal and some Common Practice commands are supported.
For a list of the commands, refer to the ROC800-Series HART-2
Module technical specification sheet (ROC800:HART2). The supported
commands conform to HART Universal Command Specification
Revision 5.1 and Common Practice Command Specification Revision 7,
(HCF SPEC 127 and 151). Refer to www.hartcomm.org for more
information on the specifications.
The HART-2 module polls the channels simultaneously. If more than
one device is connected to a channel in a multi-drop configuration, the
module polls one device per channel at a time. The HART protocol
allows one second per poll for each device, so with five devices per
channel the maximum poll time for the channel would be five seconds.
Note: The DL8000 does not support HART devices configured in
Burst mode (in which the device sends information without a
prior request). If you have a HART device configured in burst
mode, use a hand-held field communicator to turn off burst
mode before you connect the device to the DL8000.
The HART-2 module provides “loop source” power (+T) and four
channels (1+ through 4+) for communications. The +T power is current-
limited.
DL8000-powered
HART Devices
When using the DL8000 to power HART devices, connect terminal
+T in parallel to the positive (+) terminal on all of the HART devices,
regardless of the channel to which they are connected.
Wire channel 1+ to the negative (–) terminal of a single HART device,
or in parallel to the negative terminals of the devices. Likewise, wire
channel 2+ to the negative (–) terminal of a single HART device, or in
parallel to the negative terminals of a second group of HART devices
(see Figures 3-35 to 3-37).
Externally powered
HART Devices
When powering HART devices by an external device, connect the
positive (+) terminal from the power source in parallel to the positive
(+) terminal on all of the HART devices, regardless of the channel to
which they are connected.
Wire channel 1+ on the HART-2 module to the positive (+) terminal of
the HART device. Connect the power source negative (–) terminal to
the channel’s COM terminal and to the negative (–) terminal of a single
HART device, or in parallel to the negative terminals of the HART
devices.