OPP coils / drivers

There are a few things to know about controlling drivers and coils with OPP hardware.

Number

OPP coils are numbered sequentially depending on which wing board is the coil output. Wing position 0 contains coil numbers 0 to 3. Wing position 1 contains coil numbers 4 to 7. Wing position 2 contains coil numbers 8 to 11. Wing position 3 contains coil numbers 12 to 15. The coil is numbered using the position of the OPP card (starting at 0), then a ‘-‘, and finally the coil number on the card.

coils:
  some_coil:
    number: 0-12

The above example configures a coil output as the first OPP card, and the third wing board, first output. On the microprocessor card, the output is marked as 3.4 (wing port 3, position 4).

Pulse time

The OPP hardware also has the ability to specify the “pulse time”. Pulse time is the coil’s initial kick time. For example, consider the following configuration:

coils:
    some_coil:
        number: 0-12
        default_pulse_ms: 30

When MPF sends this coil a pulse command, the coil will be fired for 30ms.

Hold Power

If you want to hold a driver on at less than full power, MPF does this by using default_hold_power parameter which works for all platforms. It can range from 0.0 to 1.0 and defines the time share the coil is on (0%-100%).

The period is fixed at 16ms for OPP. To set the hold power to 25%, set default_hold_power to .25 and OPP will use 4ms/16ms = 25%.

coils:
  some_coil:
    number: 0-3
    default_pulse_ms: 32
    default_hold_power: 0.5

This will configure OPP card 0, solenoid wing 0, last solenoid to have an initial pulse of 32 ms, and then be held on at 50% power.