SLVAG20 June 2025 ISO1228
The ISO1228 is an isolated digital input receiver designed to interface with industrial PLC inputs. This supports 24V logic levels and provides robust isolation between the input and logic sides. To detect a bi-directional AC input using the ISO1228, a series diode is used to block the negative half-cycle of the signal. This protects the device and makes sure of correct detection. The diode must be rated to handle surge currents safely. With this configuration, the ISO1228 becomes a highly reliable and efficient design for PLC digital input applications.