adccommunitymod (AutomationDirect) asked a question.
Created Date: May 21,2009
Created By: Tubecut
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I am using the CLICK PLC, CMore Micro on a small project that requires reasonably accurate timing for time keeping. At first I used a timer to generate the timing but did not get accurate time keeping , probably due to scan time. I changed and used the built in 1 second _SC 7 to supply the base timing. I notice that the PLC time seems to gain about 4 seconds over a 9-12 hour period. I was hoping for something a little more accurate than that. I have considered using one of the timing interrupts and did place a interrupt to bump a DS memory (using the MATH function). It looks like the _SC7 and the interrupt keep identical time. S0, I am hoping someone else has used the interrupt as a time base for a time of day clock(?). The application is one of those set and forget environments where resetting the Time of day clock every few days/weeks might eliminate the use of the PLC (CLICK) in this project. I am thinking that perhaps placing all of the counting (hr, min, sec, days) in side of the interrupt would be the most accurate option. Then, I am not sure what the actual accuracy of the internal PLC timing is and changing to the interrupt mode for time keeping might not really improve. Anyhow, I look forward to suggestions, comments …… Thanks you in advance,\.
Created Date: May 21,2009
Created by: twbrock
I have a program for a 05 that I am using to track time for entry to a parts crib.
I use the 1 sec time base to keep time and use a atage to correct the time when needed. It should not be to hard to convert to the click.
I have to correct the time about once a month of if the power fails.
I can post it here if you are intersted.
TWBrock
Created Date: May 21,2009
Created by: milldrone
I notice that the PLC time seems to gain about 4 seconds over a 9-12 hour period. I was hoping for something a little more accurate than that.
The application is one of those set and forget environments where resetting the Time of day clock every few days/weeks might eliminate the use of the PLC (CLICK) in this project.
This seems to indicate that the 8 seconds over a day is ok, but the accumulated error is the problem.
I have used an atomic radio controlled alarm clock, like this one.
http://www.atomic-clocks.com/latepralclwi.html
I used the AC adapter, hacked the piezio buzzer circuit by adding a 3 - 30 volt solid state relay to interface with the PLC input. I set the alarm time for 2:00 in the morning. This takes care of daylight savings as well.
Created Date: May 21,2009
Created by: Tubecut
Milldrone: I like the clock, less than $30.00 and has that alarm output. That could well be the solution, but I do worry that the location to receive the radio signal might present a problem. But, with dry contact relay output, that might be just the ticket. I already have a similar clock at home and it is spot on.
Created Date: May 21,2009
Created by: milldrone
Tubecut,
If you can live without your home unit for a couple of nights, try it in the intended location and deliberately set the time wrong. If the time is reset in the morning then your good to go.
Note: The radio signal is strongest at night.
Created Date: June 01,2009
Created by: Affindadeta
CLICK CMore Micro and time
you have a fast computer to me, in a sense where a single program is considered, firefox, so id use Fast-slow, but the best way to know is to try different configs so YOU really know how fast firefox can be on your computer
Created Date: May 21,2009
Created by: Tubecut
I am using the CLICK PLC, CMore Micro on a small project that requires reasonably accurate timing for time keeping.
At first I used a timer to generate the timing but did not get accurate time keeping , probably due to scan time.
I changed and used the built in 1 second _SC 7 to supply the base timing. I notice that the PLC time seems to gain about 4 seconds over a 9-12 hour period. I was hoping for something a little more accurate than that. I have considered using one of the timing interrupts and did place a interrupt to bump a DS memory (using the MATH function). It looks like the _SC7 and the interrupt keep identical time. S0, I am hoping someone else has used the interrupt as a time base for a time of day clock(?).
The application is one of those set and forget environments where resetting the Time of day clock every few days/weeks might eliminate the use of the PLC (CLICK) in this project.
I am thinking that perhaps placing all of the counting (hr, min, sec, days) in side of the interrupt would be the most accurate option. Then, I am not sure what the actual accuracy of the internal PLC timing is and changing to the interrupt mode for time keeping might not really improve.
Anyhow, I look forward to suggestions, comments ""
Thanks you in advance,\.