Eaton Analogue Input module types MTLx541A/MTLx541AS
INTRODUCTION
Application and function
The Analogue Input module types MTLx541A/MTLx541AS (single channel) and MTLx544A/MTLx544AS
(dual channel) are intrinsic safety isolators that interface with process measurement transmitters located
in a hazardous area of a process plant. They are also designed and assessed according to IEC 61508 for
use in safety instrumented systems up to SIL 2.
The MTLx541A provides an input for a separately-powered 4/20mA transmitter located in a hazardous
area, and repeats the transmitter current into a load in the safe area. The MTLx544A supports two
identical channels for use with two separate transmitters. The MTLx541AS and MTLx544AS versions act as
a current sink for the safe area connection rather than driving the current into the load.
All the modules allow bi–directional transmission of HART communication signals superimposed on the
4/20mA loop current, so that the transmitter can be interrogated either from the operator station or by a
hand held communicator (HHC).
There are no configuration switches or operator controls to be set on the modules. These modules are
members of the MTL4500 and MTL5500 range of products.