INJECTOR POSITION SENSING

Injection systems can include a reservoir, a plunger mounted within the reservoir, and a plunger shaft including engaging the plunger within the reservoir. A motor can be coupled to the plunger shaft and can be configured to cause the plunger and plunger shaft to move within the reservoir. Systems can include a first encoder and a second encoder and a controller array in communication with the first and second encoders. The controller array can receive outputs from the first and second encoders representative of the position of the motor. Outputs from one encoder can be used to confirm the accuracy of the output of the other encoder. The controller can compare the outputs from the encoders, and, if the difference in the outputs is greater than a predetermined amount, disable operation of the motor.