Per Point Input Timestamping

As a Sequence of Events feature, you can configure an input point to timestamp the input transitions and report the timestamps on per-point basis. The timestamps are based on the system time clock from CIP Sync.

Pulse Latching

Pulse Latching is supported via the Timestamping feature and Timestamp Latching. You can use Pulse Latching to detect or latch short-duration pulses.
To use Pulse Latching, you must set the Input Data parameter to Timestamp Data in the Device Definition dialog.
Location in Studio 5000 Logix Designer Application Project
Action
Module Properties → Points → Ptxx
Check the input transition type where you must latch short-duration pulses.
For example, for short-duration pulses that are latched for Off to On transitions, select Off → On input transition.
Module tags
One or both of these actions.
  • Change the
    C.Ptxx.CaptureOffOnEn
     tag to 1.
  • Change the
    C.Ptxx.CaptureOnOffEn
     tag to 1.
When the module detects a short-duration pulse at an input point, the changes that are described in this table occur.
Input Transition Type Where Pulse Is Captured
Change in Studio 5000 Logix Designer Application Project
Off to On
  • The
    I.Ptxx.TimestampOffOnNumber
     tag increments.
  • The timestamp is recorded in the
    I.Ptxx.TimestampOffOn
     tag.
On to Off
  • The
    I.Ptxx.TimestampOnOffNumber
     tag increments.
  • The time stamp is recorded in the
    I.Ptxx.TimestampOnOff
     tag.
When subsequent short-duration pulses are detected at the same input point, the Latching configuration dictates what changes, if any, occur in the Studio 5000 Logix Designer application project.
Latching Configuration
Input Transition Type Where Pulse Is Captured
Change in Studio 5000 Logix Designer Application Project
Disabled (default)
These conditions disable Timestamp Latching.
  • The Enable Timestamp Latching checkbox on the Ptxx view is cleared.
  • The
    C.Ptxx.TimestampLatchEn
     tag = 0
Off to On
The
I.Ptxx.TimestampOffOnNumber
 tag increments.
The new time stamp is recorded in the
I.Ptxx.TimestampOffOn
 tag, which overwrites the previous time stamp.
On to Off
The
I.Ptxx.TimestampOnOffNumber
 tag increments.
The new time stamp is recorded in the
I.Ptxx.TimestampOnOff
 tag, which overwrites the previous time stamp.
Enabled
These conditions enable Timestamp Latching.
  • The Enable Timestamp Latching checkbox on the Ptxx view is selected.
  • The
    C.Ptxx.TimestampLatchEn
     tag = 1
Off to On
The
I.Ptxx.TimestampOffOnNumber
 and
I.Ptxx.TimestampOffOn
 tags remain latched until the last captured pulse is acknowledged. In other words, the tag values remain the same until the last captured pulse is acknowledged.
On to Off
The
I.Ptxx.TimestampOnOffNumber
 and
I.Ptxx.TimestampOnOff
 tags remain latched until the last captured pulse is acknowledged. In other words, the tag values remain the same until the last captured pulse is acknowledged.
To acknowledge the last captured pulse, set the output tag of the last input pulse as follows:
  • Off to On transition - Set the
    O.Ptxx.TimestampOffOnNumberAck
     tag =
    I.Ptxx.TimestampOffOnNumber
     tag.
  • On to Off transition - Set the
    O.Ptxx.TimestampOnOffNumberAck
     tag =
    I.Ptxx.TimestampOnOffNumber
     tag.
Once a pulse latch is acknowledged for an input point, the next pulse at that point increments the corresponding
I.Ptxx.TimestampOffOnNumber
 and records the time stamp in
I.Ptxx.TimestampOffOn
.
You can change tag values in program logic while normal module operation continues or through the Studio 5000 Logix Designer application tag editor.

Chatter Detection

Chatter Detection is a feature that is directly related to Timestamping. You use the feature to detect when a device that is connected to the module input causes chatter.
Chatter occurs when the device causes the inputs to transition falsely many times in a relatively short period. As a result, the module time stamps invalid input transitions.
You can configure the following:
  • Chatter Count – Determines the number of acceptable input transitions that can occur in a given time period before considering the input to be chatter.
  • Chatter Time – Determines the amount of time within which the number of input transitions are counted.
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