The MTL4046 accepts a 4/20mA floating signal from a safe-area controller to drive a current/pressure converter (or any other load up to 800_) 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 (HHC). 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 MTL4046C is identical to the MTL4046 except that it provides open circuit detection only (no short-circuit detection).

Working range

– – 4 to 20mA

Under/over range capability

– – Under range = 1.0mA

– – Over range = 26.0mA (load _520_)

Power requirement, Vs

– – 58mA at 24V dc

– – 70mA at 20V dc

– – 40mA at 35V dc

Power dissipation within unit

– – 1.2W typical at 24V with 20mA loop current

– – 1.4W worst case

Isolation

– – 250V ac between safe- and hazardous-area circuits Input circuit is floating

Safety description

– – 28V, 300_, 93mA, Um = 250V rms or dc