Siemens SITRANS LR 300 Guía Para La Puesta En Marcha página 9

P838 Auto False Echo Suppression Distance:
Defines the endpoint of the learned TVT
distance.
Range: 0.000 to 9999
Values
Preset: 1 m (or equivalent depending
on units)
Using P837 and P838: (perform this function at low tank levels)
If the reading fluctuates between the correct level and a high level, set parameters P837
and P838 to elevate the TVT (Time Varying Threshold) in this region and to de-sensitize
the receiver from any 'base noise' caused by internal antenna reflections and/or nozzle
echoes.
a. Determine the distance from flange face to liquid level.
b. Select P838 and key in [distance to liquid level minus 0.5m].
Select P837, then press 2 (Learn) and
c.
3. After you have completed programming, press
SITRANS LR 300 Communications
HART or Profibus PA
• You will need the full manual to acquire the list of applicable parameters.
• The HART Device Descriptor (DD) may be obtained from the HART Communications
Foundation at www.hartcomm.org
• We recommend that you use Simatic Process Device Manager (PDM) to program
your instrument.
• The GSD file for Profibus PA is SM_05E0.GSD: you can download it from our Web
site at: www.siemens-milltronics.com
Dolphin or Modbus connections
For communication via the RS-485 port, the unit is shipped pre-configured for Dolphin
protocol at 9600 baud, no parity, 8 data bits, one stop bit. To configure it for Modbus RTU
communications, set P770 to 3. For other changes please see the full Instruction Manual.
Maintenance
The SITRANS LR 300 requires no maintenance or cleaning under normal operating
conditions. Under severe operating conditions, the antenna may require periodic
cleaning.
Instructions specific to hazardous area installations
(Reference European ATEX Directive 94/9/EC, Annex II, 1/0/6)
The following instructions apply to equipment covered by certificate number SIRA 01ATEX1282
or SIRA 01ATEX2276:
1. For use and assembly, refer to the main instructions.
2. The equipment is certified for use as Category 1G/2G equipment.
The 1G certification covers the use of the equipment antenna or wave-guide in a
zone 0 environment at ambient temperatures of –40°C to +60°C and atmospheric
7ML19985QA82 SITRANS LR 300 – QUICK START MANUAL
P837 Auto False Echo Suppression: adjusts
the TVT curve height to ignore false echoes
on the Echo Profile.
0
Values
1 *
2
. Wait 2 seconds.
to return to RUN mode.
Off (not used)
Use learned TVT
Learn
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