1C31233G04 Emerson Ovation Contact Input Module

Description:

The Contact Input configuration (1C31233G04) provides 16 contact input current
detecting channels with common returns. The field side circuitry and terminal
connections for three of these channels are shown in Figure 21-4.
A +48V on-board power supply provides current limited contact wetting voltage if
the contact is open. If the contact closes, current is drawn from the +10V supply
which turns on the associated opto-isolator; thereby, relaying a closed contact state
to the I/O bus. The opto-isolators and the isolation provided by the 10V and 48 Volt
power supply provide high dielectric isolation between the field side and the logic
or I/O bus side.
There are two methods of wiring field devices to the termination block as shown in
Figure 21-4. Each field contact may have a separate input and return line as shown
for channel 1. Alternatively, field contacts wired to the same module may share a
return line as shown for channels 2 and 3. For either wiring method, do not tie the
contact return line to earth ground or a ground fault condition will occur, as well as
a degradation of the common mode surge protection.
Ground fault detection circuitry on the Sequence of Events module with Contact
Inputs activates when the input or return line for any channel finds a low impedance
(<5 K ohms) path to earth ground. A single wire with a ground fault will not cause
an error in the point data, but multiple ground faults, if they include input and return
lines, could cause faulty data (that is, channels appearing as if their contacts are
closed when they are really open).

Datasheet Link:

1C31233G04 Emerson Ovation Contact Input Module Datasheet