In most emergency installations, the backup gensets equipped with two independent starter batteries. 

The following programming example shows how two relay outputs are energized in turn when discrete input DI 9 is energized. For the first time, relay 11 will be energized, the second time, relay 12 will be energized, then relay 11…and so on.

This programming may be used to change between two battery sets for each starting cycle. Therefore DI 9 must be used to start the engine also / or use the DI which starts the engine, default is DI 2. Or any other input command may be used instead of DI 9, for example the command “03.06 Engine released”.

This example uses:

DI 9; Flag 02;  Flag 03; Flag 04; Flag 05; DO 11; DO 12