The MTL4544 provides fully-floating dc supplies for energising two conventional 2-wire or 3-wire 4/20mA or HART transmitters located in a hazardous area, and repeats the current in other circuits to drive two safe-area loads. For smart transmitters, the unit allows bi-directional transmission of digital communication signals superimposed on the 4/20mA loop current. Alternatively, the MTLx544S acts as a current sink for a safe-area connection rather than driving a current into the load. Separately powered current sources, such as 4-wire transmitters, can be connected but will not support HART communication
Number of channels :Two
Location of transmitter: Zone 0, IIC, T4–6 hazardous area if suitably certified Div. 1, Group A hazardous location Safe-area :output Signal range: 4 to 20mA Under/over-range: 0 to 24mA
Hazardous-area input Signal range: 0 to 24mA (including over-range)
Transmitter voltage: 16.5V at 20mA
These models have been assessed for use in IEC 61508 functional safety applications. SIL2 capable for a single device (HFT=0) SIL3 capable for multiple devices in safety redundant configurations (HFT=1) See data on MTL web site and refer to the safety manual.