C8817 is parallel remote interface GPI/O relais, it features Electrically isolated I/Os, Inverter for input logic and Inverter for output logic. Each of the 8 GPOs may be addressed from C8k modules (see module manual) by sending a predefined GPO number to the CAN bus. The C8817 is permanently listening to the CAN bus. If it reads such a number, the associated GPO will be activated. There is a maximum of 127 GPO numbers. The GPOs may be logically inverted, i.e. a N.O. relay contact becomes N.C. If one of the 8 GPI inputs is activated, the C8817 will send a predefined GPI number to the CAN bus. C8k modules are permanently listening to the CAN bus for such numbers. If any of the C8k modules reads such a number, the predefined action will be performed by the module. There is a maximum of 127 GPI numbers. The GPIs may be logically inverted, i.e. an input now needs 5V for de-activation.