The present invention is directed to a surgical instrument with a robotics system, a memory device and an end effector having an elongate channel, knife position sensor(s) and a firing bar coupled to a knife. In response to drive motions initiated by the robotics system, the firing bar may translate within the elongate channel As the firing bar translates, the sensor(s) transmit a signal to the memory device. The position of the knife may be determined from the output signals and may be communicated to the robotics system or instrument user. The sensors may be Hall Effect sensors.
