Table of Contents
Advertisement
Novajet PROe Series Service Manual
Figure 2-9. Quadrature Signal Generation.
The direction that the Carrier Assembly is moving is known based
upon the state of one detector's output and the direction of the
transition of the other detector's output.
A hardware counter in the gate array increments as the Carrier
Assembly moves left and decrements as the Carrier Assembly moves
right. The hardware counter is only eight bits wide, so it cannot
store a value large enough to represent an absolute Carrier Assembly
position. Instead, it is read during the servo interrupt and its value
compared with that from the previous interrupt. This difference is
used to update the absolute position value in the software.
Theory of Operation
37
Advertisement
Table of Contents
