Rockwell Automation 1734-IK Encoder/Counter Modules User Manual - Manual (Page 18)

Publication 1734-UM006B-EN-P - August 2005
1-8 About the Modules
New Data Indicator
A two-bit counter, C1 & C0, updates every time an "event" occurs,
indicating that new data is available in the Stored/Accumulated Count
words. Definitions for events are as follows.
• Any active gate transition in any of the Store Count (Counter or
Encoder) modes
• The end of the gate sample period in either the Period mode or
Rate mode
• The end of the programmed sample period in the Rate
Measurement mode.
To use these bits reliably, acquisition of data from the Counter Module
must occur faster than the events, which cause C1/C0 to increment.
When C1/C0 is updated, a Change Of State (COS) message can be
sent.
Default Configuration
The module's default configuration on startup is as follows.
• Counter Mode
• 50Hz filter on A, B and Z
• No time base
• Rollover = 0x00FFFFFF
• Preset = 0
• No scalar
• Counter Control Safe State = 0
To modify the default settings to those required for your application,
refer to the Input and Output section of this manual.