The ACT20X HDI SDO S / 2HDI-2SDO-S isolating switch amplifiers are specially designed for recording NAMUR sensor signals and digital switching signals which originate from Ex zone 0.

Negative-switching (NPN) transistor outputs are used to transmit the signals to applications in the safe zone.


Integrated alarm contacts issue an alert in the event of a malfunction; this makes troubleshooting easier and increases system availability.


The rail mounted disconnect-switch amplifiers are optionally available in one- or two-channel versions.
 With 11 mm width per channel, the devices need little space in the electrical cabinet.