What is meant by Rotary Incremental Encoder Index Pulse “gating”?
Gating refers to the width of the Z (index) pulse relative to the A and B channels. With ungated devices the edges of the Z pulse have no hard relation to A & B. Gating to channel A, requires the Z pulse to be high once per revolution and only when A is high. Gating to channels A&B high requires the Z pulse to be high once per revolution and only when A AND B are high. Gating to A creates a Z pulse roughly 180 Electrical Degrees in duration while gating to A&B creates a Z pulse roughly 90 Electrical Degrees in duration. Gating to a smaller duration increases the precision of the Z pulse, but also requires the motion system to be able to read the Z channel at a faster rate. Gating is sometimes required by certain drive/amplifier/controller manufacturers. QD145 Z (Index Pulse) Specifications: Ungated Z Z-A/A-Z min = 0 Electrical Degrees Z-A/A-Z max= 225 Electrical Degrees Z width min = 180 Electrical Degrees Z width Max = 540 Electrical Degrees Z Gated to A Z width min = 135 Electrical D
