ControlLogix timestamping

Hi folks,

In ControlLogix5555 there is a timestamping feature that can timestamp a time when data has changes or when fault has occurs (fuseblown, no load detection,broken wire, etc).
If I look at the monitor tag there is a tag with name CSTtimestamp.
How to demonstrate this timestamp so if there is fault on the module we can know when this fault already occurs?
Any suggest would be greatly appreciated!

Deer

Sorry that I don't know ControlLgx, but POE (Plain Old English) it would look something like this:

- create a data file to store your timestamps - be sure to leave room for your expected quantity of entries

- When Faultcondition occurs:
- check that your log file is not full/will not fill with this new entry
- Oneshot a Mov of the hour, min, and sec (if required) real-time registers into 3 successive integers, (or create a small routine to turn the time into a Julian number - I have one if you require)

- if log file is full/almost full, shuffle the entries along to discard the oldest
(MOV #N7:1 #N7:0 255)

For I/O Modules that support it, you can use timestamping, BUT you need to configure the module to present timestamped data.

When you insert a new module, the first page has a drop down field for Comm Format.. there you want to make sure you select a format with CST Timestamping.

Look up 'Timestamping inputs', 'Coordinated System Time', and 'CST' in the RSLogix5000 online help.

Hi all,

Thanks for your thought...
Yesterday, I have try timestamp feature on the Controllogix.
Using a push button that connected to a diagnostic input modul 1756-IB16D,when I push the button then timestamping value on the monitor tag will be change too.This value is in microseconds unit (example:1044876542), and everytime I push the button the value would be increase.
But this value is not represent a system clock that can stamp when the changes has occurs (let say changes has occurs on 09.00 am, etc), my next question is how to convert from this value to the base system clock?


Deer

If you are looking at the module RTS, or Rolling Time Stamp, no. That has nothing to do with the system clock. It's primarily a way of providing interval time between samples to things like Ramp blocks, and PID's, etc.

The Rolling Time Stamp applies to the module as a whole, not individual inputs.

The actual TimeStamping that I was talking about should be based on the system coordinated master clock, and will apply individually to each input/output. Again though, you have to initially configure the module to support a data format that includes time-stamping when you first create the module in the hardware rack.