Digital Output Wiring; Figure 14: Digital Output Connections For Ma Load (Hart Only); Figure 15: Digital Output Connections For Plc Counting Input (Hart Only) - Honeywell STT850 Quick Start Manual

Digital Output Wiring

Digital Output is available only on HART transmitters. The Digital Output should not
use the same power supply as used to support the 4-20mA transmitter output. See
Figure 14 and Figure 15.
For Intrinsically Safe (IS) applications, the 4-20mA and the Digital Output must use
separate IS Barriers.

Figure 14: Digital Output Connections for mA Load (HART only)

For best performance, it is recommended that:

Digital Output wires should be in a separate shielded twisted pair cable,
do not use the same cable as used for the Loop or the Sensor wires

If using the same power supply to operate both the 4-20mA Loop and
the Digital Output, then make the interconnections to the power supply
terminals directly at the power supply
NOTE: Intrinsically Safe Installations require the use of separate IS Barriers
for the 4-20mA output and for the Digital Output connections

Figure 15: Digital Output Connections for PLC Counting Input (HART only)

14 Quick Start Installation Guide
SmartLine Temperature Transmitter
September 2017