Comparator Issue

[JCURIEL]

I Have a D3-340 CPU and I'm using a Equal to Contact instruction to be true when a Timer reaches 60 seconds. When the Equal to Contact Instruction goes true, the current value for a counter will be transferred to a Register Memory and will Reset the counter. What is happening is that the timer resets on 30 seconds; if I change the number in the Equal to Contact instruction (k6000) to K12000, it will reset when th timer reaches 60 seconds. Please find attached a Doc file with a print screen of the Ladder Logic. I already contacted Automation DIrect Technical Support, but they had the same results I have. Doc1.doc

[J. B. Jennings]

Rather than using the in-line compare on rung 5 would it not be more advisable to use a T600 N.O. contact (Timer done) since the preset of the timer is 60 seconds???? Just my 2cents....

[JCURIEL]

[JCURIEL]

[JCURIEL]

I agree 100%, but I wonder why the Equal to Contact goes true at only 50% of the Timer preset.

[J. B. Jennings]

Sounds like yet another "Rounding error"......

[b_carlton]

My comparative contact won't accept K12000 as a right hand argument.

[J. B. Jennings]

Largest value allowed in right hand argument is K9999 (which happens to be the max allowed BCD number for 16 bits)

[b_carlton]

Which was leading to my doubting the completeness of the original poster's description of the problem.