Changing Default Failsafe Direction And Write Protect Jumpers; Figure 36 Location Of Failsafe And Write Protect Jumpers On Pwa - Honeywell ST 3000 User Manual

8— Operation - Changing Default Failsafe Direction and Write Protect Jumpers

Changing Default Failsafe Direction and Write Protect Jumpers

Default failsafe direction
Transmitters are shipped with a default failsafe direction of upscale. This means that the transmitter's
output will be driven upscale (maximum output) when the transmitter detects a critical status.
The upscale failsafe action will drive an analog transmitter's output to 20.8 mA or a downscale action will
drive its output to 3.8 mA.
The HART communicator parameter PV AO Alrm Typ identifies the failsafe direction of the transmitter.
The parameter indicates failsafe action as either Hi (upscale) or Lo (downscale).
Write protect option
Transmitters are shipped with a default jumper position for read and write access. This means that the
transmitter's configuration database can be overwritten.
Procedure
The procedure in Table 37 outlines the steps for cutting the failsafe jumper and/or repositioning the write
protect jumper on the transmitter's Printed Wiring Assembly (PWA). Figure 36 shows the location of the
jumpers on the PWA of ST 3000 Release 300 transmitters.
ESD HAZARD
The nature of the integrated circuitry used in the transmitter's PWA makes it susceptible to
damage by stray static discharges when it is removed from the transmitter. Follow these tips to
minimize chances of static electricity damage when handling the PWA.
• Never touch terminals, connectors, component leads, or circuits when handling the PWA.
• When removing or installing the PWA, hold it by its edges or mounting bracket only. If you
must touch the PWA circuits, be sure you are grounded by staying in contact with a
grounded surface or wearing a grounded wrist strap.
•
As soon as the PWA is removed from the transmitter, put it in an electrically conductive bag
or wrap it in aluminum foil to protect it.
Printed Wiring
Assembly
Failsafe
Direction
Jumper

Figure 36 Location of Failsafe and Write Protect Jumpers on PWA

90 ST 3000 HART Transmitter Release 300 User Manual
Write Protect
Jumper
W
R
Read and
Write
Read Only
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