Reg: Modify or Force DB Variables

[natcheappan]

Hello Everybody,

i want to modify the DB variable status, For e.g modify the variable status from false to True. but am unable to modify it. i want to know the reason. can u help me in this case.

regards
Natcheappan.N

 

[L D[AR2P#0.0]]

Is the DB variable in question being written to in the plc program ?

 

[userxyz]

Change the trigger

The program is overwriting your variable. Do a cross reference on that variable and check where in the program it is setted true. You can then do whatever you want with it, disable it for example.

Regards,
Gerry

 

[luccass]

Tell us exactly how you do it. Step by step.

 

[userxyz]

Okay

I'll do my best



Select blocks en then in the upper menu => Options -> Reference Data -> Display and you'll get:






Choose cross references and you'll get:






As an example, I can not make M2010.0 False, it remains allways high because the CPU overwrites my forcing. So click on the filter and choose in your case DB and give the DB number. I've choosen 'Bit Memory' 2010 for my example:






Then you get the filtered list of where your DB data has been used in the program. In my case I can see that the program Writes (W) to M2010.0 in FC320 NW3. So I can right click on it and select 'Go To Location':






You'll get the network where the bit is written:





You can temporary delete this network, jump over it or whatever, as long as there is not written to the output.

I hope this helps,

Regards,
Gerry

 

[natcheappan]

Thank you Gerry for your help.