4-20 mA Current Output Transmitter for Duty Cycle Input

Transmits ON or OFF period in percent of total period. DIN Rail mounted, digitally programmable.
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4-20 mA current transmitter, duty cycle input
Key Features
  • Triggers on positive or negative pulse edges
  • DIN rail mount housing only 22.5 mm wide
  • Plug-in screw-clamp connectors
  • Easy setup with PC-based Instrument Setup Software
  • 5V, 10V or 24V dc sensor excitation output, isolated
  • Dual solid state relays for alarm or control, isolated
  • Isolated 4-20 mA or 0-10V transmitter outputs, selectable
  • Transmits ON or OFF period as a percentage of total period
  • Resolution of 1%, 0.1% or 0.01%
  • Frequencies from 0.005 Hz to 10 kHz
Standard Features
  • Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
  • RS232 or RS485 serial communications, isolated
  • Universal AC power, 85-264 Vac
  • Priced at only $275 (basic duty cycle transmitter)
Options
  • Low voltage power, 10-48 Vdc or 12-32 Vac
Description

Clock diagram, 4-20 mA duty cycle transmitterThe Laureate 4-20 mA output duty cycle transmittetracks ON or OFF period as a percentage from 0% to 100% of total period of repetitive pulse trains. In the illustration, duty cycle is 100 x t/P. The transmitter determines duty cycle by averaging an integral number of periods over a gate time, which is selectable from 10 ms to 199.99 s. The same signal is applied to Channels A and B. The unit divides the average pulse width by the period between pulses and expresses this ratio in percent. A resolution of 1%, 0.1% or 0.01% is selectable. By selecting leading or falling pulse edges, the ON or OFF duty cycle can be transmitted.

Signal conditioner board, 4-20 mA duty cycle transmitter The dual-channel signal conditioner used for pulse detection accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and AC signals from 12 mV to 250 Vac. Jumper selections provide optimum operation for different sensor types and noise conditions.

Three analog transmitter settings are jumper selectable: 4-20 mA, 0-20 mA or 0-10V. The output tracks the reading from -999,999 to +999,999 counts that would be transmitted digitally. All selections provide 16-bit (0.0015%) resolution of output span and 0.02% output accuracy. Output isolation from signal and power grounds eliminates potential ground loop problems. The supply can drive 20 mA into a 500 ohm (or lower) load for 10V compliance, or 10V into a 5K ohm (or higher) load for 2 mA compliance.

Standard features of Laureate temperature transmitters include:

  • Analog transmitter output,16-bit, user scalable and isolated. User selectable 4-20 mA, 0-20 mA or 0-10V levels.
  • Serial communications,isolated. User selectable RS232 or RS485, half or full duplex, Modbus or Laurel ASCII protocol.
  • Dual solid state relays for control or alarm,isolated. Rated 120 mA at 130 Vac or 170 Vdc.
  • Universal AC power supplyfor 85-264 Vac. Low voltage power of 10-48 Vdc or 12-32 Vac is optional.

Easy Transmitter programming is via Laurel's Instrument Setup Software, which runs on a PC under MS Windows. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL04).