Hart Or Profibus Pa - Siemens SITRANS LR 300 Guía Para La Puesta En Marcha

False Echo Suppression using P837 and P838:
If the SITRANS LR 300 incorrectly displays full level, or if the reading fluctuates between
a high level and a correct 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. Perform this function at low tank levels.
b. Determine the distance from flange face to liquid level.
c. Select P838 and key in [distance to liquid level minus 0.5m].
Select P837: press 2 (Learn) and then press ENTER
d.
Learned TVT) automatically after a few seconds.
3. After you have completed programming, press PROGRAM
HART/Analog Output
The analog output responds in the following manner:
P001 = 1 (level)
100%
P006
empty
P007
span
level
0%
0 and 100% are percentage of full-scale reading (m, cm, mm, ft, in).
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.
Page EN-8 SITRANS LR 300 – QUICK START MANUAL
P001 = 2 (space)
20 mA 0%
space
P006
empty
P007
span level
4mA
100%
. P 837 will revert to 1 (use
to return to RUN mode.
P001 = 3 (distance)
0%
distance
4 mA
P006
empty
P007
span level
20 mA
100%
4 mA
20 mA
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