Sequence of Events Recorder

Hello everyone,
Has anyone worked on Sequence of Events Recorder in any system.
Can anyone brief it out tome or explain me what it is all about ?


Thanking you in advance

The sequence of events recorder will log data (usually I/O status with a real time clock) and store the data in the PLC/Computer. The data can then be reviewed at a latter time.

I like to think of this as a robust logging system because the data is stored in the PLC (Real Time) and it can then be retrieved when needed.

http://accautomation.ca/now-you-can-have-robust-data-logging-for-free-part-1/

Note: Some systems will go down to the millisecond time frame

Regards,
Garry
http://www.accautomation.ca

Our controller has an event log that will record I/O, calculation results, transitions from one state to the next and communications in intervals as fine as 250 micro seconds.

It is very handy for detecting errors and what led up to them and what happened after.

There are two basic ways to accomplish SOE. You can have SOE capable input modules that time stamp usually to 1 ms. This normally requires that you have the system connected to a GPS clock to normalize the time system wide.
Option 2 is that you have a standalone SOE system that is connected to the process inputs such as the following: http://www.mehtatech.com/

Usually the PLC option is less expensive if you already have a PLC in the scope.

Additionally, if you have electrical protection relays in your supply then these relays normally are connected to a time clock via IRIG b. The relays will internally time stamp the protection actions to a 1 ms accuracy. This is for modern numerical multi function relays.