A420

The A420 is a RS-232 To 20mA Current Loop Converter provides optical isolation and transient protection. The device is full duplex point-to-point communication using only 4 wires (one pair each for receive and transmit data). The device has optically isolated data lines and high speed data transfers, 19200bps over 400 metres and a maximum data rate of 64Kbps. The 20mA current loop breaks the ground loop at each end so the device is suitable for inter-building communications where different ground potentials can make RS-232 unreliable.

• Uses Hewlett Packard opto-couplers for 20mA
• Available as a pre-set, fully isolated pair (2500VAC for 1 minute)
• Screw terminal connector on 20mA side
• Current loop transmit and receive lines are switch selectable for ACTIVE and PASSIVE
• Switchable DCE/DTE selection for RS-232 port
• LED indicators for data activity
• Can be used in multidrop environments
• Optically coupled 20mA transmitter and receiver
• Configurable RD and TD loops as Active or Passive
• Reverse polarity protection
• Standard DB25 used for RS-232 interface

Applications

Communications & Networking