Allen-Bradley MicroLogix 1200 Reference Manual page 91

Table 5.11 HSC Mode 7 Examples
Input I1:0.0/0 (HSC0)
Terminals
I1:0.0/4 (HSC1)
Function Count A
⇑
(2)
Example 1
⇓
(3)
Example 2
⇓ off (0)
Example3
Example 4 on (1)
Example 5
Example 6
Example 7
(1) HSC1 only applies to the MicroLogix 1500.
(2) Count input A leads count input B.
(3) Count input B leads count input A.
⇑
Blank cells = don't care, = rising edge,
HSC Mode 7 - Quadrature Counter (phased inputs A and B) With External Reset
and Hold
(1)
I1:0.0/1 (HSC0) I1:0.0/2 (HSC0)
I1:0.0/5 (HSC1) I1:0.0/6 (HSC1)
Count B Z reset
off (0)
off (0)
off (0)
on (1)
⇓
= falling edge
NOTE
I1:0.0/3 (HSC0)
I1:0.0/7 (HSC1)
Hold
off (0)
on (1)
off (0) on (1)
off (0)
Inputs I1:0.0/0 through I1:0.0/7 are available for use as
inputs to other functions regardless of the HSC being
used.
Using the High-Speed Counter
CE Comments
Bit
off (0) on (1) HSC Accumulator + 1 count
off (0) on (1) HSC Accumulator - 1 count
Reset accumulator to zero
Hold accumulator value
Hold accumulator value
Hold accumulator value
off (0) Hold accumulator value
Publication 1762-RM001C-EN-P
5-21