Can the outputs be switched to ground instead of supply voltage?

This can be found in the data sheet of the respective module. By default, e.g. used on the CAN I / O or Micro PLC-CAN High Side Driver, that means that these only switch on the supply voltage. When PROP-CAN or motor controller 5 A and 10 A is sitting on output C, an open collector transistor, which switches to ground.