Table of Contents
Advertisement
Communications
The SITRANS LC500 is equipped with HART communication
values can be obtained and altered locally
Typical PLC configuration with HART
power supply
SITRANS LC500
Diagnostics
The internal diagnostic functions continuously monitor the operation of the transmitter.
An error signal is generated if a failure or irregularity occurs.
The SITRANS LC500 sends the signal current according to the NAMUR NE 43
recommendation. During normal operation the current remains within the range from 3.8
to 20.5 mA. If the process exceeds its normal limits but is not in a fault or failure situation,
the signal current will be outside the measurement range (4 to 20 mA) but will be limited
to either 3.8 or 20.5 mA.
If a fault or a failure is detected, the signal current is set to either 3.6 mA or 22 mA,
depending on the settings you have chosen. (This feature may be disabled by the user.)
1.
Depending on the system design, the power supply may be separate from the
PLC, or it may be part of the PLC.
2.
A 250 Ohm resistor is required only when the PLC is connected to a HART
modem or a HART communicator.
3.
The HART communicator and a PCL/laptop computer cannot both be connected
to the 4-20 mA loop simultaneously.
Page 34
SITRANS LC500 – OPERATING INSTRUCTIONS
1
2
= 250
R
PC/laptop with Simatic PDM or HART communicator
1
protocol
3
or remotely.
2
so that settings and
3
7ML19985GE04
Advertisement
Table of Contents
