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https://www.lakeshore.com/240/
Model 240 Quick Start Guide
Power and Communication
Connection
To minimize shock hazard, the instrument is equipped
with a grounded connection to the DIN rail. Connect the
DIN rail to an electrical ground.
Power
The typical power supply is 24 VDC, but can range
from 21.6 VDC to 26.4 VDC. The power supply should be
capable of supplying at least 100 mA per module.
RS-485/PROFIBUS interface
The
RS-485/PROFIBUS-DP communication integrates
with distributed PLC-based control architectures.
Sensor Input Connection
For best results, voltage leads (V+ and V-) and current
leads (I+ and I-) should be twisted together. The twisted
pairs of voltage and current leads should then be
covered with a braided or foil shield that is connected
to the shield pin of the instrument. This type of cable is
available through local electronics suppliers. Instrument
specifications are given assuming 3 m (10 ft) of sensor
cable. Longer cables can be used, but environmental
conditions may degrade accuracy and noise
specifications.
The sensor inputs are isolated from earth ground to
reduce noise pickup. The shield should not be connected
to earth ground at the modules. One shield should
be connected to an earth ground near the sensors.
Connecting at more than one point will cause a ground
loop, which adds noise to the measurement.
PWR+ DC power supply positive
PWR- DC power supply return
B+
PROFIBUS signal
A-
PROFIBUS signal
I+
Positive current
V+
Positive voltage
SH
Shield
V-
Negative voltage
I-
Negative current
