How do you provide an LED status indicator with ISO121x digital input receiver devices?
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
In many cases, having an indicator LED is preferable whether it is on the controller side or field side. They often interface with users and will need to be isolated for operator safety, and usually used with current limiting resistors to protect the diode. And the outputs of the isolated digital receivers can drive the indicator LEDs by providing different currents depending on source voltage VCC1. In the case of having an LED indicator on the field side, the signal carrying current can be routed in an inner layer of the PCB without compromising the isolation. For more information on board layout please refer to this thread and the ISO121x datasheet.