MicroLogix Scan Time: Is S:22 in Usec or MSec?

[MorphuisOGrady]

Hi there,

For my piece of mind:

In the processor status of my Micrologix online I am getting a reading of 23 in S:22. This is a reading of x100uSec.

Am i correct in saying this is 2300uSec/2.3 mSecs?

If so great, fast processor for its price, otherwise bummer I'm getting towards my limits!!!

 

[TConnolly]

Micrologix 1000? scan time is S:13 * 10 milliseconds = s:13*.01, or .230 seconds.

Micrologix 1100? scan time is S:13 * 100 microseconds = S:13*.0001, or .0023 seconds.

 

[Mickey]

Micrologix 1000? scan time is S:13 * 10 milliseconds = s:13*.01, or .230 seconds.

Micrologix 1100? scan time is S:13 * 100 microseconds = S:13*.0001, or .0023 seconds.

HMMM?

I see
S:22= Max Scan time for all Micrologix Controllers.

S:3= Last Scan time for ML1000

S:35= Last Scan Time for all other ML's

 

[MorphuisOGrady]

Sorry, wasnt too specific. Micrologix 1400

 

[TConnolly]

HMMM?

I see
S:22= Max Scan time for all Micrologix Controllers.

S:3= Last Scan time for ML1000

S:35= Last Scan Time for all other ML's

Where the hell did S:13 come from? Thats the math register.

Don't know what I was thinking when that came out. 'Proll some kind of pebcack error.


Good catch.

 

[dash]

Yes, that is x100 micro-seconds, so you are correct. A 23 would be 2.3 milli-seconds. As you obviously know micro is 10^-6 and milli is 10^-3.

But, the online help is a little confusing for this line of PLCs. It states that the max scan time does not include the overhead tasks (comms, reading inputs, writing outputs), which I thought the SLC platform included that overhead in the Max Scan. Anyway, depending on what you are doing the overhead time may ruin what you thought was fast.

From help file:
MicroLogix 1100/1200/1400/1500 Scan Times Status

Maximum [x100 uSec] S:22
This word indicates the maximum observed interval between consecutive program cycles. The I/O scan, processor overhead, and communication servicing is not included in this measurement.


Darren

I have reread that help file statement a few times and it does not make since. If it is the max time between TWO CONSECUTIVE cycles, how would this NOT have the additional overhead included. That is odd.