The MTL4646 accepts a 4/20mA floating signal from a safearea controller to drive a current/pressure converter (or any other load up to 800Ω). 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 MTL4646Y is very similar except that it provides open circuit detection only
Number of channels:One
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
Communications supported:HART
LED indicator:Green: power indication
Maximum current consumption (with 20mA signals into 250Ω load):35mA at 24V dc
Power dissipation within unit (with 20mA signals into 250Ω load):0.8W at 24V
MTL4676-RTD
MTL4675
MTL4649/Y
MTL4646/Y
MTL4644/S
MTL4644D
MTL4632
MTL4628
MTL4627
MTL4626
MTL4624S
MTL4624
MTL4623L