Why plant gain (k) not included in tuning formulas table?

Question

hi,
why plaint Gain is not included in tuning table, is there any specific reason.
due to whic most of the students makes mistakes while calculating PID values using identified model manually and there calculated value doesnt match with the value frovided with labview.
http://zone.ni.com/reference/en-XX/help/370401J-01/lvpidmain/ziegnichforms/

Answer 1

Hi ,  
  This is a sort of performance issue , because your program takes more than the max time set for the program to execute in foreground.
There are many stuff in program which will hamper your performance.
I will list down a few
1. SELECT *
FROM konp
INTO CORRESPONDING FIELDS OF TABLE konp_itab
FOR ALL ENTRIES IN a363_itab
WHERE knumh EQ a363_itab-knumh
in this statement you are using for all entries a363_itab , but before this statement you are not checking if the table has any entry or not , please do remember that for all entries has this characterstic , that if you internal table does not contain any record , then all the records are selected from the database table. So in this case if you table a363_itab is empty , so what you want is no data must be seelcted from table konp , but what will happen is all the records in KONP will be seelcted.
2. While retreiving data you are using seelct * even though you do not require all the fields , an example is
<b>SELECT *
FROM mkpf
INTO CORRESPONDING FIELDS OF TABLE mkpf_itab
FOR ALL ENTRIES IN mseg_itab
WHERE mblnr EQ mseg_itab-mblnr.</b>
in this your internal table contains only 2 fields
<b>mblnr LIKE mkpf-mblnr, "Number of Material Document
bldat LIKE mkpf-bldat, "Document Date in Document</b> , but to get these 2 fields you are selecting all the fields of the table.
3. In select you are using into corresponding fields of table , it is not a good practice., so please avoidd it.
Please understand that you must try to reduce the access to your database tables and try to keep it minimal , because this same thing may happen becasue data in DEV is very less compared to the volume of data in production , so a program working in DEV will take much more time in PRD if not written properly and may result in timeouts , as in your case.
Please try to make chanegs to the prorgam and see if it works.
In case you have more queries , please do revert back.
Regards
Arun
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