These outputs are usually used for muting HPAs during switching cycle of an assigned waveguide switch. Nevertheless these outputs also can be used as simple digital outputs. Please refer to chapter 2.4.3 Photomos-relay digital outputs to learn how to define if these outputs are hardware controlled by inbit matrix or by software. In contrast to the former sat-nms IO-FEP(-E), photomos-relay outputs at this new sat-nms IO-FEP2 are closed when IO-FEP2's power is off. So if the unit fails, your transmission will not be interrupted by this issue! if you nevertheless need to have normally open contacts, please refer to chapter 2.6 Replacing an existing sat-nms IO-FEP(-E) by IO-FEP2 to learn how to solve this issue.
For each output there is one red LED available showing actual state. As these outputs usually are used to mute HPAs, corresponding red LED is ON, when contact is OPEN, so connected HPA is in mute state. If LED is OFF, corresponding output is CLOSED and connected HPA is transmitting.
Take care not exceed ratings of these switches: maximum 48V/130mA is allowed. On-state resistance is 18Ohm typ. (25Ohm max.).