John Shearer Pasture Renovation Drill Operator's Manual page 59

Jackal - Grain & Fertilizer Shaft Monitoring
The distributor shafts have a magnet embedded in them which together with a sensor can be used to
monitor shaft rotations. An alarm can be set to warn you if the shaft speed drops below a certain
amount (see section 3.2.1.2 of the Farmscan Jackal Manual). We suggest setting a low figure so that
the alarm will give a warning if the shaft stops turning for some reason when seeding.
The shaft sensors, as well as the standard area sensor can be connected to inputs B1-6 with the white
wire (note: if you expect to use a coil sensor, do not use port B1). The black ground wire for each sensor
all connect to port A1. See section 6.3.1 of the Jackal Manual for more information.
The sensors will need to be calibrated on the Jackal monitor as shown in section 4 of the Jackal
Manual (note: these are 'Digital inputs').