Mtl5549/ Mtl5549Y - Isolating Driver - Eaton MTL5501-SR Instruction Manual

6 .5 .2

MTL5549/ MTL5549Y - Isolating Driver

Two channel, for 4/20mA HART® valve positioners with line-fault detection
The MTL5549 accepts 4/20mA floating signals from safe-area controllers to drive 2 current/
pressure converters (or any other load up to 800Ω) in a hazardous area. For HART valve
positioners, the module also permits bi-directional transmission of digital communication
signals so that the device can be interrogated either from the operator station or by a hand-held
communicator. Process controllers with a readback facility can detect open or short circuits in
the field wiring: if these occur, the current taken into the terminals drops to a preset level. The
MTL5549Y is very similar to the MTL5549 except that it provides open circuit detection only
(i.e. no short-circuit detection).
MTL5549
PWR
MTL5549Y
PWR
Figure 6 .26:
Top labels
for MTL5549
& MTL5549Y
Input characteristics
INM 5500 Rev 10
Hazardous area Safe area
Ch 2
6
+
P 5
4/20mA
4
I
–
3
+
P 2
4/20mA
1
I
–
Ch 1
Terminal Function
1 Output –ve (Ch 1)
2 Output +ve (Ch 1)
4 Output –ve (Ch 2)
5 Output +ve (Ch 2)
8 Input –ve (Ch 2)
9 Input +ve (Ch 2)
11 Input –ve (Ch 1)
12 Input +ve (Ch 1)
13 Supply –ve
14 Supply +ve
Field wiring state MTL5549
Normal
Open-circuit
Short-circuit
Ch 2
7
I
–
8
4/20mA
9
I
+
Ch 1
10
I
–
11
4/20mA
12
I
+
13
14
20 to 35V dc
MTL5549Y
<6.0V <6.0V
<0.9mA <0.5mA
<0.9mA N.A.
Vs–
Vs+
47