Intermec IF61 GPIO Terminal Block User's Guide - Page 18

Because the outputs are optically isolated, you can configure each one to switch the high side or the low side of the load. You can power the load directly from the reader or from an external power supply. The next examples illustrate several ways to connect controls to the output terminals: • Switching the high side, with the load powered by the reader. • Switching the low side, with the load powered by the reader. • Switching the high side, with the load powered externally. If the load being switched requires more than 6 W, you need to provide external power. • Driving a DC relay that controls an AC load. Switching the High Side Using Reader Power The terminal block is factory configured for high side switching, with power coming from the reader. Only the single output being switched is affected if the interface cable fails. This configuration supports many indicator lamp applications. By default, the LED indicator for each output terminal is wired in parallel with the output load, giving visual feedback to users when the output from the reader has changed state. Each output terminal includes a jumper that shorts the +12 V and +Output posts. Connect the output load to the -Output and Ground posts as seen in the next illustration. Reader interface 12 V 500 mA max. Input Ground External indicator lamp 0.25 A maximum Switching the High Side 18 GPIO Terminal Block User's Guide