MTL5546/Y Safety Barrier (Analogue Output)

MTL4546/c/Y – MTL5546/Y
ISOLATING DRIVER
for 4–20mA HART® valve positioners 
with line fault detection

The MTLx546 accepts a 4/20mA floating signal from a safe-area controller
to drive a current/pressure converter (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. 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 MTL4546C and the MTLx546Y are very similar
to the MTLx546 except that they provide open circuit detection only  
(i.e. no short-circuit detection).
 

SPECIFICATION
number of channels
One
Location of I/P converter
Zone 0, IIC, T4–6 hazardous area if suitably certified
Div. 1, Group A, hazardous location
Working range
4 to 20mA
Digital signal bandwidth
500Hz to 10kHz
Maximum load resistance
800Ω (16V at 20mA)
Minimum load resistance
90Ω (short-circuit detection at < 50Ω)
output resistance
> 1MΩ
under/over range capability
Under range = 1mA
Over range = 24mA (load ≤ 520Ω)
Input and output circuit ripple
< 40µA peak-to-peak
Transfer accuracy at 20°c
Better than 20µA
Temperature drift
< 1.0µA/°C
Input characteristics
Field wiring state MTLx546 MTL4546c MTLx546Y
Normal < 6.0V < 6.0V < 6.0V
Open-circuit < 0.9mA < 0.9mA < 0.5mA
Short-circuit < 0.9mA N.A. N.A.
response time
Settles within 200µA of final value within 100ms
communications supported
HART

MTL Barriers