Rockwell Automation 1734-IB4D POINT I/O 24V dc 4-Channel Discrete Input Module Installation Instructions - Manual (Page 9)

POINT I/O 24V dc Digital Diagnostics Input Module 9
Publication 1734-IN029A-EN-E - January 2007
Understand Open-wire Detection
Sensor source voltage (SSV) current for each input is monitored.
Monitoring is accomplished in the SSV leg to accommodate the
largest number of sensors possible. For currents below 0.5 mA, a fault
signal is issued and the input's LED indicator blinks red. On a
per-input basis, the circuit and produced data automatically reset
upon removal of the open-wire condition. See the information about
interpreting LED indicators for related information.
By using a configuration tool, you can disable the open- wire
diagnostics on an input-point basis to keep unused input indicators
from turning red and signaling a fault when an input is not in use.
Enabling or disabling input-point level open-wire diagnostics is
implemented via the module’s EDS file, GSD file, or Logix profile and
its firmware.
You can also disable all the open-wire diagnostics, using a single
entry via the software user interface. The default configuration has
all four input channels’ open-wire indication enabled.
If a sensor with a dry contact output is used, wire one side of the
contact to the SSV terminal for the corresponding input. Wire the
other side of the contact to the input. Additionally, place a shunt
resistor in parallel with the contact, at the sensor, to cause greater
than 0.5 mA to be drawn through the SSV terminal at all times.
Install the Mounting Base
To install the mounting base on the DIN rail, proceed as follows.
1. Position the mounting base vertically above the installed units,
for example, adapter, power supply, or existing module.
2. Slide the mounting base down so that the interlocking side
pieces engage the adjacent module or adapter.