IM_1XTXSW-08
www.ueonline.com
8
HART
®
WIRING AND OPERATION
No separate wiring is required for digital communication with HART
®
devices since the HART
®
FSK (Frequency Shift Keying) signal is superimposed
on top of the 4-20 mA output signal. Digital data is sent to and from the One Series via a HART
®
communicator while real-time process informa-
tion is available via the 4-20 mA signal. A twisted pair or shielded wire cable is recommended where extended lengths are required or electrical
noise may be present.
For Bench Testing, connect the One Series to a power supply and a load resistor (see Figure 10). A voltmeter across the 250 Ω resistor can be
used to measure the current in the loop ( Iloop = Vresistor / 250 ). At 4 mA the voltmeter will read 1 volt and at 20 mA the meter will read 5
volts.
For Field Operation, the One Series can be connected to any HART
®
compatible input card, module or, if the HART
®
interface is not being used,
any standard 4-20mA input (see Figure 9). In most cases the power supply and the load resistor are built into the input card or module, allowing
direct connect with no external load resistor.
NOTE:
Before attempting to change the polling address, UE recommends installing the One Series device descriptions (DDs) on your handheld or
software application. Installation instructions for Device Descriptions (DD) as well as DD files may be found at www.ueonline.com/products/hazard-
ous-location/one-series/ under HART
®
Protocol Resources. Once the DDs have been properly installed, the One Series can be fully accessed and
is ready to receive the Universal, Common Practice and Device Specific commands that can be found within table 5, page 17-18 of this manual.
By default, the polling address of the One Series 1XTX is set to “0”. To be accessible through a HART
®
network with multiple HART
®
devices, the
One Series must be in multi-drop mode by setting the polling address to a number other than “0”. The polling address can be changed by using
a HART
®
Handheld Communicator or HART
®
modem and software to any value between 1 and 63. Choose an address that is not being used by
another device in the HART
®
network.
Input
Card/Module
One
Series
One
Series1
One
Series2
One
Series15
TB1+
TB1-
TB1+
TB1-
TB1+
TB1-
TB1+
TB1-
Power
Supply
One
Series
TB1+
TB1-
+
-
+
-
+
-
250 Ω
1-5 VDC
HART
®
Comm
Field Operation
Multi-Drop Mode
Bench Testing
…
Input
Card/Module
Figure 9
Figure 10
