Got it running with the following code:
int PCFStatus1;
// Gets the byte value from many input/coil status.
PCFStatus1 = get_byte_from_bits(mb_mapping.tab_coil_status, 0, 8);
PCF8574Write(byte(PCFStatus1));
Got it running with the following code:
int PCFStatus1;
// Gets the byte value from many input/coil status.
PCFStatus1 = get_byte_from_bits(mb_mapping.tab_coil_status, 0, 8);
PCF8574Write(byte(PCFStatus1));