arnoldzw

Exceed maximum step size

8 posts in this topic

Hi guys!

 

Need some help from the real specialists! :shrug:

 

I`am used to work normally with Scheider Unity and make my program`s always in function blocks.

Now working on my first GXworks2 project, and programmed the whole project also in FBD.

 

I have an FX2N-32MR plc, and defined in the configuration the maximum step size of the cpu to 8000 steps.

I have compiled my program successfully, but the result gives an program size of 10217 steps. (and i`m not finished programming yet)

 

Converting the program to ladder or ST is not possible i think....?  (and i`am not very familiar with those languages)

Add additional memory card is also not possible because of the type installation.

Did have some self-made function blocks inside, but they are very simple.

 

 

How is counting of steps working in GXworks2?

Are the 8000 steps for the complete project, or per POU, so than split into pou,s will reduce steps?? 

Strange is when i add one single BIT move block into the program, and compile again. Program size becomes 10229.  (so the one move block is 12 steps?)

 

Are there any tips for reducing the memory/program  load? 

 

 

5c7449370103c_Mitsubishicompile.png.3d05

Edited by arnoldzw

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Hi Arnoldzw.

Unfortunatley there is no simple way to reduce this significantly; you may be able to use different instructions/ functions to reduce your step size, however the only significant way to reduce this is to use a different language such as simple/ structured ladder etc.

Normally with a Mitsubishi system; the code would be designed and coded before buying the necessary hardware- this way you can approximate the number of steps so that you can then choose an appropriate CPU.

You also should ensure you have a spare number of steps to accommodate the online change facility if this is something you wish to do during your comissioning stages.

Ultimatley; your most cost effective measure will probably be to buy a bigger CPU.

 

Regards

Daniel

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Hello,

is there any reason why you simply cant rise memory capacity to 16k?

memory.PNG

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8 hours ago, collinsd70 said:

Hi Arnoldzw.

Unfortunatley there is no simple way to reduce this significantly; you may be able to use different instructions/ functions to reduce your step size, however the only significant way to reduce this is to use a different language such as simple/ structured ladder etc.

Normally with a Mitsubishi system; the code would be designed and coded before buying the necessary hardware- this way you can approximate the number of steps so that you can then choose an appropriate CPU.

You also should ensure you have a spare number of steps to accommodate the online change facility if this is something you wish to do during your comissioning stages.

Ultimatley; your most cost effective measure will probably be to buy a bigger CPU.

 

Regards

Daniel

Thank you Daniel,

 

Correct, but these are re-fits for an current installation where the PLC needs to stay unfortunally.

Maybe its good to reprogram some parts into ST or ladder.  Do you know what language takes the less step sizes? Ladder of ST?

 

 

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52 minutes ago, sczot said:

Hello,

is there any reason why you simply cant rise memory capacity to 16k?

memory.PNG

Thank you sczot,

The CPU is limited to 8K, so 16K wont work.

 

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8 hours ago, arnoldzw said:

Thank you Daniel,

 

Correct, but these are re-fits for an current installation where the PLC needs to stay unfortunally.

Maybe its good to reprogram some parts into ST or ladder.  Do you know what language takes the less step sizes? Ladder of ST?

 

 

Hi Arnoldzw

 

It seems you are in a very difficult position. At this point in time; I would consider which is most cost effective 1. The time it will take you reengineer this code, test and debug or 2. Bite the bullet and buy a PLC with suitable step size.

You will have to play around with languages to work out which translates into less steps.

 

Regards

 

Daniel

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On 26. 2. 2019 at 7:29 AM, arnoldzw said:
On 26. 2. 2019 at 7:29 AM, arnoldzw said:

Thank you sczot,

The CPU is limited to 8K, so 16K wont work.

 

Thank you sczot,

The CPU is limited to 8K, so 16K wont work.

 

now i see...

have you considered using of FX-EEPROM-16? It is just memory cassette, so there is no need to rebuild your old machine. You  can search ebay, but our local mitsu dealer is still offering them...

Simple ladder is in theory most efficient, when it comes to step size

 

 

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Hard to offer advice without seeing the program but program size reduction was covered recently:

 

FX3U would be the current equivalent of an FX2N. 

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