OTC-22: Loop-Powered Optical Signal Isolator          specsheet  


  • Ideal for PLC-to-Transmitter Interfacing
  • Connects to PLC like a Two-Wire Transmitter
  • High Input-Output-Power Isolation (1500VAC Test)
  • Small Size - Fits on Terminal Block Rail
  • Fast Response Time (typ. 1 msec)
  • Industry Standard 4-20mA Input and Output
  • Loop-Powered - No External Power Required
  • High Noise Rejection
  • CSA and NRTL Approved (LR51078)

The OTC-22 provides high isolation from Input to Output in a small, easy to install package. The universal DIN rail mount often makes it possible to install the OTC-22 right next to the instrument that is to be isolated.

The OTC-22 is optically isolated to eliminate all electrical interference from input to output. Two-wire inputs and outputs require no external power to be applied to the OTC-22. The unit simply uses the existing power in the 4-20mA input & output loops. This makes it very easy to retrofit existing installations that show signal instability due to ground loops etc.

These properties make the OTC-22 ideal for front-end interfacing on PLC’s that have two-wire inputs only. The OTC-22 essentially acts like a two-wire transmitter on the PLC side (OTC-22 output) and like a standard load on the transmitter side (OTC-22 input).

  • Isolation: 1500 VAC Input to Output to Power (Test)
  • Power: Loop-Powered (8.7V min. Required in 4-20mA loops)
  • Accuracy/Linearity: +/-0.1% max., +/- 0.05% typ.
  • Common Mode Rejection.: at 60 Hz = 120 dB
  • Response Time: 1 msec to 99% of final value
  • Temperature Effects: +/- 0.2% max., +/-0.1% typ. (for 50 Deg. C. change)
  • Operating Temperature:-40 Deg. C. to + 50 Deg. C.