Allen-Bradley A-B QUALITY DL20 Series User Manual page 104

Chapter 8
Special Functions
Setting Up I/O
Port Functions
8–16
Setting Parallel Port
If you selected time driven sampling, you are prompted for the type of inputs
used.
Answer [Y] for AC sampling if you are using:
A 2706-NG1 or -NG2 Series A or B Parallel Input Converter
Answer [N] for DC sampling if you are using:
DC inputs
Catalog No. 2706-NG1 or -NG2 Series C or later Parallel Input Converter
When specifying time driven samples, you must provide a scan rate.
The scan rate is the period between samplings in units of 1/512 seconds (1.95
ms).
For DC sampling, the range for the scan rate is 4 to 255
(7.8 ms to 500 ms).
For AC sampling the range for the scan rate is 28 to 255
(54.6 ms to 500 ms).
The DL20 always samples the data more than once. If all of the samples do
not agree, the data is ignored and not scanned again until the next sampling
period.
If you are using DC inputs or a Parallel Input Converter (Catalog No.
2706-NG1, -NG2 Series C or later), you must provide a debounce time:
During the debounce time, data samples are read every 1/512 second (1.95
ms). The allowable range is from 1 to 255 (1.95 through 500 ms).
Increasing the debounce time provides better noise immunity. Decreasing
the debounce time provides a faster response. The debounce time should be
3 less than the scan rate.
USE NG1/2 SER A,B?
SCAN RATE: 25
DEBOUNCE TIME: 2