Siemens SITRANS P - Manual (Page 32)

SITRANS P measuring instruments for pressure
Transmitters for food, pharmaceuticals and biotechnology
SITRANS P300 for gage and absolute pressure
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The input pressure (pe) is transferred to the absolute pressure
sensor (5) via the seal diaphragm (3) and the filling liquid (4),
displacing its measuring diaphragm. The displacement
changes the resistance value of the four piezo resistors in the
measuring diaphragm in a bridge circuit. The change in the re-
sistance causes a bridge output voltage proportional to the input
pressure.
Parameterization of SITRANS P300
Depending on the version, there are a range of options for pa-
rameterizing the pressure transmitter and for setting or scanning
the parameters.
Parameterization using the input keys (local operation)
With the input keys you can easily set the most important param-
eters without any additional equipment.
Parameterization using HART communication
Parameterization using HART communication is performed with
a HART communicator or a PC.
Communication between a HART communicator and a pressure transmit-
ter
When parameterizing with the HART communicator, the connec-
tion is made directly to the 2-wire system.
HART communication between a PC communicator and a pressure
transmitter
When parameterizing with a PC, the connection is made through
a HART modem.
The signals needed for communication in conformity with the
HART 5.x or 6.x protocols are superimposed on the output cur-
rent using the Frequency Shift Keying (FSK) method.
Adjustable parameters on SITRANS P300 with HART communi-
cation
Diagnostic functions for SITRANS P300 with HART communica-
tion
• Zero correction display
• Event counter
• Limit transmitter
• Saturation alarm
• Slave pointer
• Simulation functions
• Maintenance timer
Available physical units of display for SITRANS P300 with HART
communication
+
HART
communicator
230 ... 1100 W
transmitter
SITRANS P Power supply
transmitter
SITRANS P Power supply
HART
modem
PC or
laptop
RS 232
230 ... 500 W
Parameters Input keys HART com-
munication
Start of scale x x
Full-scale value x x
Electrical damping x x
Start-of-scale value without application
of a pressure ("Blind setting") x x
Full-scale value without application of a
pressure ("Blind setting") x x
Zero adjustment x x
Current transmitter x x
Fault current x x
Disabling of keys, write protection x x 1)
1) Cancel apart from write protection
Type of dimension and actual dimension x x
Input of characteristic x
Freely-programmable LCD x
Diagnostics functions x
Physical variable Physical dimensions
Pressure (setting can also be made
in the factory) Pa, MPa, kPa, bar, mbar, torr, atm,
psi, g/cm
2
, kg/cm
2
, inH
2
O, inH
2
O
(4 °C), mmH
2
O, ftH
2
O (20 °C),
inHg, mmHg
Level (height data) m, cm, mm, ft, in
Volume m 3 , dm 3 , hl, yd 3 , ft 3 , in 3 , US gal-
lon, lmp. gallon, bushel, barrel,
barrel liquid
Mass g, kg, t, lb, Ston, Lton, oz
Temperature K, °C, °F, °R
Miscellaneous %, mA
© Siemens AG 2008