ML 1100 High Speed counter- 1 or 4?

Hi all, I have a simple application that I intend to design around a Micrologix 1100. The hitch is that I have two 5khz inputs that I wish to count. I am confused on the wording in the selection guide- it states theat there is 'one embedded 20khz high-speed counter' on one page, but later states under 'High-Speed Inputs (pulse catch)' that there are four @ 20khz. I am not familiar with the pulse catch inputs; can I use any combination of the 4 to consistently see the two 5khz channels?

If this won't fly, any leads on remote high speed cards that will interface with the 1100 will be greatly appreciated.

if you want to use them simultaneously it is 1. you have four inputs to use them as you wish, but when comes to counting if you count in same time they will overlap resulting in losing counts.
that's why they are saying you have only HSC.

I might be wrong for 5Khz, but I tested for 10Khz on ML1500 who has 8 high speed inputs but only 2HSC files by default, and with a good reason. when I tried to count 4 HSC in same time for arount 10Khz I lost counts.

If you won't use them in same time is ok.

You have HSC module for ML1500 but the problem with it is if loses power loses counts. it is not battery backed-up.
1769-HSC High-speed Counter Module

I did buy the 1769 HSC card but it is a different form factor and according to AB is not compatible. Is there a way to use it as a remote device? I just need to do some simple switching - for example, count 6000 pulses and turn off a motor- so if there is a simple logic device that could handle it internally that would be fine. I looked extensively and am surprised there isn't a Red Lion or similar counter that can accept a preset from a remote device, that would be about perfect for the job.

Thanks again for any advice.

The MicroLogix 1000, 1100, and 1200 have only one hardware high-speed counter.

The MicroLogix 1500 has two.

I think you need the MicroLogix 1500 controller for this application. Ordinary counters or fast pulse-catch inputs won't successfully read a 5 kHz signal, but the hardware HSC circuits will.

If you bought the 1769-HSC I guess you can by the ML1500 to go with and you are set.

Is far as i know 1769-HSC goes only on backplane for ML1500 and Compactlogix

So, if your inputs are not in same time, you can use ML1100 - one HSC file and one EII file.

If you use them in same time i will go with ML1500 - two HSC
(not to mention that you already have the 1769-HSC module)

I do not understood what you mean RedLion counters do not accept preset from a remote device.

From what you said till now looks like the C48C will be good for you.

Stauby said:

I did buy the 1769 HSC card but it is a different form factor and according to AB is not compatible. Is there a way to use it as a remote device? I just need to do some simple switching - for example, count 6000 pulses and turn off a motor- so if there is a simple logic device that could handle it internally that would be fine. I looked extensively and am surprised there isn't a Red Lion or similar counter that can accept a preset from a remote device, that would be about perfect for the job.

Thanks again for any advice.

Click to expand...

Take a look at Durant, I have a few installed, where the PLC sends an ASCII message to the Druant for the preset and source.

There are four input interrupts available on top of the HSC in ML1100.
They may be configured for inputs 4 to 7 and user programmed for counting.
But I am not sure about ability to count 5kHz without lost interrupts.
I would arrange a diagnostic loopback on the ML1100 and count PTO pulses by the interrupt, in order to find the top frequency limit without lost counts.
It will also somewhat depend on the main program size and organization.
Try to keep rungs short and increase the watchdog timer setting to acceptable maximum.

Great tips. My program will be small and primarily error handling. It looks tight but I may be able to swing reading the pulses.

I'll look more into the ascii and RS-485 options in case the timing doesn't work out.