The following drawing shows how four Single Pole Double Throw switches can be used in a Homemade switch box to connect to an Ag Leader Auxiliary Input Module.

A dumb switch box (meaning CAN is not involved inside it) is necessary to work with an Auxiliary Input Module. The number of switches could range from 1 to about 15 or so.

Ag Leader makes a single toggle switch for one section rigs and a 10 section with Master switch box for other situations. I made my own switch box for a previous planter and included some switches in it for other purposes. Another alternative is so use Ag Leader's SC110 CAN switch box. It is a switch box that contains a Master and 10 sub switches and the CAN circuitry built inside so the Auxiliary Input module is not used. Either of these can be used. I have a SC110 in my planter tractor and an Auxiliary Input Module connected to the Master and Section switches in my Hagie sprayer.

The switch box can be constructed using Single Pole Double Throw switches. The switch box can also be constructed using Single Pole Single Throw switches and diodes. I have done this both ways.

The diagram below shows the Single Pole Double Throw switch approach. Note that the top terminals of each switch are connected to the module pin called Switch Detect. That pin is usually ground but is 12V at certain times. The bottom terminals of each switch are connected to the module pin called 12V out. This pin is always 12V. The center terminals of the switches go back to the module to locations F1-F4. F1-F4 are not in order so a chart is helpful. I have one somewhere.

Since each switch is a double throw type, the center terminal will be connected to its bottom terminal when the lever is flipped UP. The center terminal will be connected to the upper terminal when the lever is flipped DOWN. In other words the center terminal is always connected to one or the other of the outer terminals.

You might ask why this is necessary. I'm not completely sure but I believe this is done so that the system only needs to check the switch locations that are actually being used. Since there are some 15 or so possible locations for switches, it would be inefficient to check each one constantly. I believe the system makes an internal chart of where actual switches are present and then only checks on those locations to determine which ones are involved in the voting process I described above. It updates this chart occasionally.

The way it creates this chart is that every once in a while (15 seconds I think) the system diverts from its usual activities and performs a Switch Presence routine in software. It makes the Switch Detect wire go to 12V. It then checks all the potential switch locations looking for 12V on each of them. Those that have 12V on them are considered to be real switches. Those locations that report back zero are considered to not contain a working switch. A chart is created accordingly.

That means that if a switch is present it will return 12V whether the switch lever is UP or DOWN. Those locations that show 12V are marked in the chart. After this short routine is run, Switch detect returns to ground and the system returns to normal and then just checks the locations that appear to have switches as to whether the switch is ON or in the other position which acts as OFF.

Below is a rough drawing of a switch box using four switches. Should more switches be useful such as shutting off the strip til separately they would be wired in a similiar fashion. There really isn't much of a current load on each switch since they are just acting as inputs and are not directly opening the valves anyway

(AIM wiring (full).JPG)

AIM wiring (full).JPG (57KB - 22 downloads)