Set The Jumpers For Hart/De; Setting Failsafe Direction And Write Protect Jumpers - Honeywell STT850 Quick Start Manual

SET THE JUMPERS FOR HART/DE

Setting Failsafe Direction and Write Protect Jumpers

The SmartLine Temperature
Transmitter (DE or HART) provides
two jumpers to set the desired
failsafe action and Write Protect
option. See Figure 16
The top jumper on the electronics
module sets the Failsafe direction.
The default setting is up-scale
failsafe.
Up Scale drives the loop to a value
greater than 21mA while Down
Scale drives the loop to a value less
than 3.8mA.
You can change the failsafe
direction by moving the Failsafe
Jumper (top jumper) to the desired
position (UP or DOWN).
If your transmitter is operating in DE
mode, the upscale failsafe action
will cause the transmitter to
generate a
"+ infinity" digital signal, while a
downscale failsafe will cause the
transmitter to generate a "– infinity"
digital signal.
The bottom jumper sets the Write
Protect. The default setting is OFF
(Un-protected).
When set to the On (Protected)
position, Changed configuration
parameters cannot be written to the
transmitter.
When set to the OFF (Un-protected)
position, Changed configuration
parameters can be written to the
transmitter.
16
Step
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2
3
4
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6
Quick Start Installation Guide
SmartLine Temperature Transmitter
ATTENTION: Electrostatic Discharge
(ESD) hazards. Observe precautions
for handling electrostatic sensitive
devices
Action
Turn OFF Transmitter power.
Loosen the end-cap lock, and
unscrew the end cap from the
Electronics side of the Transmitter
housing.
If there is a Display module, carefully
depress the tabs on the sides of the
Display Module and pull it off.
If necessary, move the interface
connector from the Communication
Module. Do not discard connector
Set the Failsafe Jumper (top jumper)
to the desired action (UP or DOWN).
And the Write Protect jumper
(Bottom jumper) to the desired
behavior (Protected or Unprotected)
See Figure 17 for jumper positioning.
If applicable, re-install the Display
module as follows:
• Orient the display as desired.
• Install the Interface Connector in
the Display module such that it will
mate with the socket for the display
in the Communication module.
• Carefully line up the display, and
snap it into place. Verify that the two
tabs on the sides of the display latch.
Screw on the end cap and tighten the
end-cap lock. Turn ON Transmitter
power.
September 2017