S7-1200 multi-dimensional lookup table

[marko18]

Hello all,

I am working on a project with an s7-1200 and I am controlling three stepper motors using this controller. I will be receiving input data from an external sensor, and using this data to jog the three stepper motors to pre-determined positions. I have all the possible positions in an excel file lookup table.

The issue with this lookup table is it has two inputs and three outputs (temperature and pressure are inputs, and for each combination of temperature/pressure, the table has a motor position for each of the three motors.) The possible motor positions were found via simulation and do not have any mathematical equations that tie them to the inputs. I was wondering if implementing this lookup table would be possible with the s7-1200, and if so what is the easiest way?

 

[Rob...]

Yes, quite easy.

The S7-1200 can utilize SCL and multi dimensional arrays. Which makes this kind of work fairly straight forward.

 

[marko18]

Yes, quite easy.

The S7-1200 can utilize SCL and multi dimensional arrays. Which makes this kind of work fairly straight forward.

I see. So I would have to use SCL? I've only used ladder and am not even very experienced with that. Is there a way I can import the excel file with SCL or just have it read the file automatically? There are 1000+ entries

 

[Rob...]

You can indirect address arrays in LAD, just more long winded.

 

[drbitboy]

how many input dimensions per motor? It sounds like 2 (temperature and pressure).

are the ranges for each input constant across the table? E.g. do the data in one motor's eXcel worksheet have a header row with cells like "0<P(ressure)<=10," "10<P<=25," "25<P<50," etc., and another column down the left with cells like "32<T(emperature)<=40," "40<T<45," etc., and then all the values at each row an column inside those headers are the motor positions?

 

[kalabdel]

I see. So I would have to use SCL? I've only used ladder and am not even very experienced with that. Is there a way I can import the excel file with SCL or just have it read the file automatically? There are 1000+ entries

To get the data in and out, you can use csv files. See this for ideas, and if you have HMI capable of recipe management, that would also be a way to go.