MAN0878-09-EN_XLE_XLT_UserManual
A u g u s t 2 3 , 2 0 1 8
P a g e 88 | 158
Three different options are available to reset (or set) the current count.
•
Configured Counts per Rev value
When configuring the quadrature function, a value may be specified under the Counts
per Rev column. When rotation produces an increasing count, the quadrature
accumulator resets to zero on reaching the Counts per Rev count. Alternately, when
rotation produces a decreasing count, the quadrature accumulator is set to Counts per
Rev
–
1 on the count following zero. Specifying zero for this value allows the totalizer to
count through the full 32-bit range before resetting.
For example, if your encoder outputs 1024 counts per revolution, the value of 1024 can
be entered into the configuration for Counts per rev. This will result in a counter that
produces counts in the range of 0 to 1023.
•
Ladder control
Setting registers %Q17 or Q19 resets quadrature (HSC) 1 or quadrature (HSC) 3
(respectively) with no additional configuration. Setting registers %Q18 or Q20 sets
quadrature (HSC) 1 or quadrature (HSC) 3 (respectively) to Counts per Rev
–
1.
•
Direct digital input control (HSC3) [Marker]
When HSC input 1 and 2 are used for quadrature inputs, an additional choice of marker
input becomes available for HSC input 3. The marker input is typically part of an
encoder or motion system that signals when a cycle of motion is complete. When the
marker input is triggered, the accumulator is reset to zero or to Counts per rev - 1
based on rotation direction.
Marker reset operation is enabled when HSC3 is configured for Marker type. Once
selected, one of several modes is available for marker operation. These modes can be
sub-divided into two groups of marker operation.
