Rockwell Automation 1746-HSCE2 Multi-Channel High Speed Counter Module - Manual (Page 22)

Publication 1746-UM002B-EN-P - August 2004
2-2 Module Operation
Input Configurations Input configurations determine how the A and B inputs cause the
counter to increment or decrement. The six available configurations
are:
• Pulse/External Direction
• Pulse/Internal Direction
• Up and Down Pulses
• X1 Quadrature Encoder
• X2 Quadrature Encoder
• X4 Quadrature Encoder
See the Summary of Available Counter Configurations on page 2-8 for
the input configurations available for the counters, based on operating
mode.
Pulse/External Direction
With this configuration, the B input controls the direction of the
counter, as shown below. If the B input is low (0), the counter
increments on the rising edges of input A. If the input B is high (1),
the counter decrements on the rising edges of input A.
Figure 2.2 Pulse/External Direction Configuration
1 2 3 2 1 0 1 2
Input A
Encoder or Sensor
Count Pulse
Count Pulse
Count
Input B
Input Z
Direction Control
Sensor or Switch
Direction Control
High = Decrement
Low = Increment