Without knowing the EMI immunity of the layout, you must consider the breakdown voltages for each terminal to protect it from excess reverse voltage One diode could be used for this purpose especially with inductive lines and open circuit with current. Keep the Current loop small in area with coax or twisted pair and you may still need a CM choke.
Beware of ESD damage and use whatever protection diodes, TVS etc to protect the device leads and capacitive discharge on connections.