plcyoulater

Micro800 family scan time?

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I cannot seem to find any information about scan times for the AB Micro800 family, specifically looking at the 850.  I have a MicroLogix 1400 sitting here and just some basic IO looks like it is in the 1ms range.  What can I expect from the 850 (from some simple IO operations)?  Thanks!

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Scan time is dependent on the processor, IO, AND how much program load there is...

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I realize this, but I am just looking for a ballpark for this processor for basic IO.  Will it be down to 1ms, or more like 10ms?

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The 1400 isn't going to run at 1ms with a program in it. I just pulled one of our 1400 programs up (godaweful thing with 9 routines that someone else wrote and we inherited). It's running between 19ms and 21ms with a peak at 37ms. It's a very simple program. Most routines have 3 or 4 rungs in them. Quite a few counters. No PID loops. Some analog scaling. They are "talking" to it with a serial radio and the ethernet port. Two IO cards

And then I logged on to an ML1100  with a LACT program I wrote a while back-. It's a bit larger program. 10 routines. Very few rungs in most routines.  It's running between 39ms and 42ms with a peak at 56ms. Some counters and timers. No PID loops. Analog input and output scaling. No radio comm. Just ethernet.

If I had to guess, and that's all it would be, the 850 is going to fall in the range above. I have one around here somewhere but I've never loaded a program in it.. 

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On 7/29/2016 at 5:20 PM, Michael Lloyd said:

The 1400 isn't going to run at 1ms with a program in it. I just pulled one of our 1400 programs up (godaweful thing with 9 routines that someone else wrote and we inherited). It's running between 19ms and 21ms with a peak at 37ms. It's a very simple program. Most routines have 3 or 4 rungs in them. Quite a few counters. No PID loops. Some analog scaling. They are "talking" to it with a serial radio and the ethernet port. Two IO cards

And then I logged on to an ML1100  with a LACT program I wrote a while back-. It's a bit larger program. 10 routines. Very few rungs in most routines.  It's running between 39ms and 42ms with a peak at 56ms. Some counters and timers. No PID loops. Analog input and output scaling. No radio comm. Just ethernet.

If I had to guess, and that's all it would be, the 850 is going to fall in the range above. I have one around here somewhere but I've never loaded a program in it.. 

You might be reading the scan times wrong, or you have a little more than simple programs. The scan times are x100 microseconds, i.e. a scan time of 19 means 1.9ms. The typical programs I do for my company's well testing skids run in 5ms scan times or less, 3ms if implement my own scheduling.

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On 7/28/2016 at 1:18 PM, plcyoulater said:

I realize this, but I am just looking for a ballpark for this processor for basic IO.  Will it be down to 1ms, or more like 10ms?

I have yet to use any of the Micro800 series, but AFAICT from product literature the same program should be faster on a Micro800 series PLC vs. a MicroLogix. I want to say that basic instruction times were about 1/5th the time.

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1 hour ago, Epy said:

You might be reading the scan times wrong, or you have a little more than simple programs. The scan times are x100 microseconds, i.e. a scan time of 19 means 1.9ms. The typical programs I do for my company's well testing skids run in 5ms scan times or less, 3ms if implement my own scheduling.

I'm sure I was looking at it wrong. The first program is very simple. The second program controls a LACT so there is a little more to it than the first one. But compared to a pump station it's nothing. I (happily) spend most of my time programming CLX.

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