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dtesterman

Ana PLC extension timers

16 posts in this topic

We are needing to add additional timers to some programs that have all the original designated timers used. (T0~T255) We are using GX-DEV and have followed what we think are the correct parameter settings for adding the new extension timers, ( the parameter check function msg states all OK!), but when trying to program these timers into the program we are receiving an error msg stating that we are either not entering correctly or there are some other issues. Currently, no one at our location has experience with using these timers so we are at some loss.

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Which CPU are you using Rodney

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As far as I can tell, AnA CPUs have 256 timers...that's it. I've never heard of 'extension timers'. Can you provide more details? Btw here is device window for A3A CPU.

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If every timer is used and needed, I suppose it is possible to make some psudo timers. You could use counters and an internal clock pulse (depending on finesse of timer wanted) to pulse the counter. You have not said which model you are using. If its an A series then you get as many counters as timers.

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I forgot to mention the information of the type of plc we are using. We are using the A2USH cpu. Sorry for the mislabeling of the type of plc. Panic Mode, on the lower part of the screen that you have displayed it has the configuration area for the extension timers. To enable the extension timers, you must first change the "timer all points" number by the increase you desire, by 16 bit count. After doing this, it can then be allocated as to the number of low, high, and/or retentative timers that are being added. This appears to be working correctly, as far as I can tell.

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As far as I am aware, the replies already posted for this query are correct i.e. 256 timers is your lot. I believe that you may be misunderstanding the term "extension timers" as it appears in the GX PLC parameters. Mitsubishi timers can either work as 1) standard devices that enter their timing function when the input conditions are true, are reset when the input condition is off and are also reset by PLC Halt 2) continued devices (Medoc) or extension devices (GX) which means that once the timer is initiated removal of the input condition causes the timing to stop at the value at that point. Re-instatement of the input condition allows the timer to continue to time from the point at which it was interrupted, hence "continued" or "extended" timing is realised giving an accumulated time up to the preset value. These timers may also be battery backed to give a retentive function preventing reset by the PLC being turned off. (Retentive function is often confused with the continue function). For more timers, as has been stated, use a system flag to increment (with a "P" modifier?) a data register but watch out for your scan time in relation to the flag time base and other issues that may affect the overall accuracy. Namedyt Niloc

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I had tried to post an excerpt earlier from the manual that list the "expansion timers", some manuals that I have list as extension, others as expansion. This references that you can change by parameters to allow up to a total of 2048 timers, with default being 256, also you can add counters up to a total of 1024, with the default being 256. I am sure that I am overlooking something, just was hoping that someone had used this function and could coach me. For some reason, probably our network here, I cannot attach anything to my post. I am referenceing the PDF IB_NA_66789-C, downloaded from the www.meau.com website.

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you mean something like this:

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may i ask what do you need so many timers for? just curious....

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This is for an automated assembly line, each machine is doing quite a bit of work. We are not the designer, it was designed by one of our company's other branches. We are the end user and are having to modify and make additional changes to the machine as we add new products and processes. The line uses CC-Link for intercommunication of the line and also network communication to the production and engineering groups. By nature of design, the PLC is undersized for the job, the designer did not allow enough area to use LS for checking extend and retract of actuators, they only check the home position only. They did not allow any expansion area, already using an expansion rack but not allowing enough space to add another without adding another cabinet. Going back to the statement about checking the actuators for only home position, they are using timers for every assembly process for every actuator. This has taken all of the area that is designated for the timers, this being before we have even started to do the modifications.

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ok, i see... you know that you could use same timer for both timeouts (cylinder extend and retract) since they never happen at the same time.

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That is a good point, my problem is that they are using the timers to set the actuation of the station, they are not using the timers as confirmation of movement for timeouts. Example: From home, if part on loader, rail clamp close, traverse forward, rotary turn up, P&P cylinder down, vacuum on, chuck cylinder close, return up, P&P traverse forward,....... Oh well, I think you get the picture, they are using a timer for each step of each motion of the actuation. With a total of 14 plus processing stations on each machine, this has ate a lot of timers up. If they had only used a larger platform and actually used LS to confirm each motion for return and extend, this would have been much simplier and way less of a headache. Naturally, when you are dealing with pnuematics, using a timer to confirm motion is a bit dangerous!

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Thanks to Ted @ Mitsubishi tech support, ( very good professional support! ) I have an answer, I will prepare some screen shots and attempt to post these here tonight!

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Here are the parameters, didn't have an issue there.

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When entering the timer, we were under the understanding that the timer would be entered with the "D, W, or R" values....... Wrong!!! You only enter the timer number, IE: T288

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After the timer has been entered, it will automatically attach the data register number that was assigned from the parameters screen. This is the "setting val. stored dev. start" that we assigned in the parameters field.

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