INTRODUCTION
The SEM215
is a universal DIN rail mount temperature
transmitter that accepts most commonly used temperature sensors,
Slidewire transducer or Millivolt signals, isolates and transmits them
as a 4 to 20 ma signal to a host system. It can be
configured by either of the following methods:
Configuration using "Quick
Selector"
One of 59 pre-set ranges can be selected by using switches.
The switch, located close to the rail clip, is inaccessible in normal
use. This "Quick Selector" method does not require any
additional calibration, and the transmitter can be put into service
immediately after selection is made.
Configuration via PC
The sensor type and user defined range are easily programmed
using a PC and a simple Windows based software program. This allows
for reprogramming or interrogation of the SEM215
while it is installed in the loop. Sensors can be changed without the
need for recalibration. Special sensors can be accommodated by
using the type "X" option, the characterization for these
sensors are factory entered for later retrieval from the menus.
The transmitter uses a two part
terminal connection which employs the latest in tension clamp
technology. Connections are therefore quick and easy to make.
Terminations are maintenance free since the contacts are always under
tension. This also eliminates the problem of contacts loosening
due to temperature fluctuations or vibration
INPUTS
Pt100 Platinum resistance sensors,
Thermocouples, millivolts or Slidewire sensors may be connected to the
unit, plus a Type "X" linearization option which may be
pre-configured at the factory to satisfy any custom characterization
requirements.
The Process Variable may be filtered to remove
incoming signal noise using one of four settings. If the
‘Adaptive’ function is selected the filter continuously adjusts to
the incoming signal to noise ratio in order to choose an appropriate
level of filtering. In this way a slowly changing input can be
heavily filtered but if the signal goes through a sudden change the
filter quickly reduces allowing a rapid response, other settings are;
off, 2 seconds, 10 seconds.
A user programmable offset is
available to remove any system errors that may be present and sensor
referencing enables the transmitter to be accurately matched to a
particular sensor.
CURRENT OUTPUT
In normal operation the current output
varies between 4 and 20 ma. If the input sensor develops a fault, or
the software in either of the two microprocessors detects an error,
then the current output is driven either upscale (greater the 20 ma)
or downscale (less than 4 ma) depending upon the sense of the burnout
parameter selected.
