At present , there's a SLC5/05 that only knows if the line is down or not. Then there's the PC that runs the scrolling display.

What would be the better solution, to have the PLC monitor the downtime and send it to the PC, or to have the PC do everything?

In the case of the former, what would I need to send the data to the PC?

And in the case of the latter, where can I get a discrete input card ( 24VDC ) for the PC? And how hard is it to program in VB to get data from cards like that?

Sorry if this is confusing, I am kinda in over my head on this one.

Help!

Thanks in advance!

 

hello M_Fehervari

Depending on how many lines you want to monitor, i have two options. For one line program to clocks in the PLC and send the accum. time to the display. Or put a HMI on the plc and use the real time clock in it to handle the up/down time. For a plant wide data colection you should use a SCADA program. hope this helps.

calvin smith
[email protected]

 

I would suggest to go forthe option 1 of doing it in PLC since you already have PLC and which will be actually acquiring the data in a more realtime manner. Also you need not spend for extra PC card for this. You may have to write some software to output this data from PLC port at some frquency and you can read it at the PC side using a small port reading software in VB or C again. You can also use a HMI/SCADA if feasible to get the data to PC.

However, if you want to go for 2nd option, you can find the PC cards either at Dynalog or Advantech.

I hope it helps,
Hemant Patil

 

Sounds like something we tried some years ago and eventually evolved into a full SCADA system.
We started out using RSView (very affordable) and played with that for a year or so. We found that we were able to easily get graphic indications of down times, up times, etc. with some simple changes to PLC programs and a very basic network hooked up to the PC.

As our needs evolved... we eventually installed RSSQL for data acquisiton and used Plantmetrics for report generation.
I would recommend experimenting with RSView (or equivalent) as a starting point.