INM 5500 Rev 11
46
6 .4 .5
MTL5544D - Repeater Power Supply
Two channel, for 4/20mA HART® for 2- or 3-wire transmitters, two outputs
The MTL5544D provides a fully-floating dc supply for energising a conventional 2- or 3-wire
4/20mA transmitter located in a hazardous area, and repeats the current in other circuits
to drive two safe-area loads. For HART 2-wire transmitters, the unit allows bi-directional
transmission of digital communication signals superimposed on the 4/20mA loop current via
channel 1 only,Separately powered current sources, such as 4-wire transmitters, can be
connected but will not support HART communication.
Hazardous area
Safe area
Vs–
Vs+
20 to 35V dc
Ch 2
Ch 1
–
4/20mA
Load
+
–
4/20mA
Load
+
4/20mA
6
5
4
3
2
1
7
8
9
10
11
12
13
14
Com
Tx+
Input
I
I
I
Terminal
Function
1
Current input
2
Transmitter ve
3
Common
7
Ch2 ve via 220Ω HART not supported.
8
Ch2 output –ve
9
Ch2 ve
10
Ch1 ve via 220Ω for HART apps.
11
Ch1 output –ve
12
Ch1 ve
13
Supply –ve
14
ve
NOTE:
For correct operation of the module, a suitable load must be present on
both
output channels.
This is of particular importance during testing, commissioning or maintenance activities when the
temporary disconnection, or absence, of a load can affect the transfer accuracy of the analogue variable.
Figure 6 .24:
Top label
for MTL5544D
