The DRA-CSM-1 Current
Multiplexer is a solid state
multiplexer capable of transferring
the selected 4-20 mA input current
signal to the output terminals in less
than 10 microseconds at an
accuracy better than 0.01%. The
DRA-CSM-1 is typically controlled
by a PLC thereby obtaining full data
synchronization.
The DRA-CSM-1 is provided with a
unit enable/disable control line
which enables the parallel
connection of several multiplexers
to the same controller input. The
period during which the unit is
disabled is used for self-testing
according to a self-test procedure
which checks the unit’s hardware.
Model DRA-CSM-1 is powered by
an external DC power supply. Each
two-wire 4-20 mA transmitter is
connected to the input terminals.
Each channel provides a current
limited voltage supply for the connected two-wire transmitter. The
channel selected by the multiplexer
is directed to the control device’s
(e.g., PLC’s) analog inputs. Power
is maintained by the multiplexer to
the unselected channels thereby
maintaining uninterrupted
transmitter current flow. Each
4-20 mA input channel on the
multiplexer has its own red LED
status light which illuminates on
presence of current in the loop.
