The photo right is the array of treadle swithches. If your weaving program does not sequence things correctly, check these switches.
The top switch, T1, is actuated by a plunger pushed in when the foot rest is forward; ie, the resting position.
The middle switch, T2, is released when the treadle is going down.
The bottom swithc, T3, is actuated when the treadle is down.
By putting the treadle in various positions you can manually actuate each switch. Doing so you should hear a clear sharp "click". If you don't hear the click, or the arm is loose and wobbly, the switch will not work correctly resulting in poor or missing signal to the software.
To test T1 you can set the foot rest in the heel back position and have someone push/release the plunger while you listen to the switch.