![]() ![]() ![]() Instead of changing the timer preset in the TON instruction, open the AOI definition dialog box and select the Local Tags tab. ![]() The reason it's greyed out is because you made the changes in the AOI's ladder logic, not in the parameter editor. That's where that checkbox comes in handy. This is good design practice of course - if you have 200 instances already in your code, and each of them has had their timer preset adjusted according to their application, having them all of a sudden set back to default just because you changed the definition would be a terrible outcome! But, at the same time, sometimes you do want all of your 200 instances to be updated with the new "default" value. However, any instances that already existed will not be updated. Any new instances of that AOI you create after you adjust that preset will be created with the same timer preset as your definition. then the preset you specified is the default for that AOI. Set a preset in that TON/TOF/RTO instruction Assign "My_AOI_Timer" to that TON/TOF/RTO Within the AOI, put a TON/TOF/RTO on a rung Have a local AOI parameter called "My_AOI_Timer" I just tried an offline edit to one of the previous existing timer presets but the instances don't show the change, although a logical edit is reflected in all instances.įor a timer, the default value is the value set in the definition. As the local tags show the correct (non zero) value for all timer presets in the offline version, I'd interpret those values as being the defaults. If you perform the test above, that should confirm things one way or the other.įor what it's worth, I've never seen a download cause any such symptoms, but I've been caught out by the "copy default values" trick a few times!ĪSF, I did see the copy all default values option but it remains greyed-out and unchecked when the timer presets are altered. So if your issue is as you described it, this may be unrelated - but it's plausible that you edited an AOI and downloaded it, then noticed the issue, and mistakenly thought the issue occurred when you downloaded, not when you made the edit. This would occur not when you downloaded, but when you clicked "OK" on the AOI definition editor. If the timer preset in your AOI instance has a default value of zero, and you updated the AOI with this option selected, all instances would be set to zero. When you update an AOI for which there are existing instances, there is an option to "copy all default values of parameters and local tags whose values were modified to all tags of this instruction type". So all direct references to Timer PRE and ACC are PCE flagged for review.If you change the timer preset of one of your instances online, save the program, and download again, does it retain its preset? This will give you a 200 milliseconds PREset, instead of the required 200 seconds. However, you are now MOVing 200 to the TIMER PRE, and not 200,000. Now you could just remove the PCE without editing and the MOV will then validate ok. remove the PCE, and revalidate the rung. So the conversion flags the rung with the MOV instruction, that references the PRE, with a PCE instruction, invalidating that rung, and forcing you to have to review it. This is beyond the capabilities of the Tool. It's not clever enough to know that it is now MOVing that Constant to a DINT that is now using a value 1000 times greater than before, and so multiplying 200 x 1000 and setting the converted MOV instruction's Constant value to 200,000. This is setting the PRE to 200s, but because it is a Constant value, the Translation Tool retains the value during conversion. If a Constant value was being MOVed to a Timer PRE in an SLC and the Timer's timebase was 1.0s, then the Constant value would have been set for a 1.0s timebase. So the Timer instructions should function as before and should not need a PCE. The conversion of the SLC Timers' timebase is usually handled ok. You're probably working from memory, but it's not exactly the TIMER instructions that are flagged with a Program Conversion Error (PCE), but more any direct references to the PRE and ACC DINTs themselves. This is the reason all TIMER instructions are flagged with conversion "errors" when you convert a PLC/SLC program, so you'll check to see if the program is using the. In ControlLogix and CompactLogix, the only timebase available is 1 millisecond. ![]()
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