Digital System Integration Information; Wiring Variations - Honeywell STT700 SmartLine User Manual

For HART and DE, the transmitter is designed to operate in a two-wire power/current loop with loop
resistance and power supply voltage within the operating range; see Figure
remote meter, the voltage drop for this must be added to the basic power supply voltage requirements,
to determine the required transmitter voltage (V
Additional consideration is required when selecting intrinsic safety barriers to ensure that they will
supply at least minimum transmitter voltage (V
resistance (typically within the barriers) needed for digital communications.
Transmitter loop parameters are as follows:
R = maximum loop resistance (barriers plus wiring) that will allow proper transmitter
LOOP MAX
operation and is calculated as R
In this calculation:
V = 10.8 V
XMTR MIN
V = 2.3 V if using EU or Remote meter, 0V if not using EU or Remote meter
SM
Note that V should only be considered if an EU meter will be connected to the transmitter.
SM
The positive and negative loop wires are connected to the positive (+) and negative (–) terminals on
the STT700.
Barriers can be installed per Honeywell's instructions for transmitters to be used in intrinsically safe
applications.
Note: Problems detected as non-critical diagnostics may affect performance without driving the
analog output to the programmed burnout level (for HART only). For DE, the burnout direction
needs to be selected in the hardware and this will be detected at power on time.

3.4.2. Digital System Integration Information

DE transmitters that are to be digitally integrated to Honeywell's Total Plant Solution (TPS) system
will be connected to the temperature transmitter Interface Module in the Process Manager, Advanced
Process Manager or High Performance Process Manager through a Field Termination Assembly.
Details about the TPS system connections are given in the PM/APM SmartLine Transmitter
Integration Manual, PM12-410, which is part of the TDC 3000
When digitally integrating a transmitter in an Allen Bradley Programmable Logic Controller (PLC)
process system, the same Field Terminal Assembly (FTA) and wiring procedures used with
Honeywell's TPS system are also used with the Allen-Bradley 1771 and 1746 platforms.

3.4.3. Wiring Variations

The above procedures are used to connect power to a transmitter. For loop wiring, sensor wiring and
external wiring, detailed drawings are provided for transmitter installation in non-intrinsically safe
areas and for intrinsically safe loops in hazardous area locations.
If you are using the transmitter with Honeywell's TPS system, see PM/APM SmartLine Transmitter
Integration Manual, PM12-410, which is part of the TDC 3000
Page 18
XMTR
XMTR MIN
= (V
LOOP MAX SUPPLY MIN
STT700 Temperature Transmitter User's Manual
) and maximum loop resistance (R
), including the required 250 ohms of
)  21.8 mA.
– V
- V
XMTR MIN SM
X
system bookset.
X
system bookset.
9. With an optional
).
LOOP MAX
Revision 2