S7-200 Micro/Win DataBlock question

[micgent]

Or, which is I think where you started, put values in the Data Block. The advantage of the Data Block is that all values are in one place, and so, easy to find. From the main screen click on Data Block or View/Component/Data Block, define a value such as:

VW100 320
// Integer - Information to remind you what VW100 does
VD102 400.567
// Float/Real - Information to remind you what VD102 does. Float values must have a decimal point, even if it is followed by 0.

You might be able to put the comment on the same line as the variable but I can't remember. Text after the // is treated as comment. If the supercapacitor is exhausted then the PLC will load the values from the Data Block. If you need to modify values you can make the changes then just download the Data Block. The disadvantage is that you will intialise all other variables to zero.

Bryan

Bryan thats spot on thank you

mg

 

[micgent]

Is it ok to write the ladder program and save it as a project before I receive the Hardware. Just I cant find anywhere on the drop down menu where I tell it what CPU and Aux Modules I wish to use?

 

[Paul B]

Right click the CPU and select Type...

 

[BryanG]

The software is pretty relaxed about the PLC type, it will only complain when you try to compile the program. It will give errors about the amount of memory you have used. When you come to download to the PLC it will ask if you want to modify the program to match the attached PLC. As Paul B said, if you want to set the PLC you can right click CPU in the top of the second pane of MicroWin or from the menu you can go PLC/Type.

Unlike a lot of other PLC programming software you don't have to specify expansion blocks but you do have to know which position an expansion will occupy in relation to the PLC and other expansion blocks. For instance an S7-222 CPU has 8I and 6Q which use points I0.0 to I0.7 and Q0.0 to Q0.5, if you add a digital 8I/8Q block then it's inputs and outputs will be I1.0 to I1.7 and Q1.0 to Q1.7. If however you add that same block to an S7-224 the range will be I2.0 to I2.7 and Q2.0 to Q2.7 because the base PLC already uses the I1.0 to I1.7 and Q1.0 to Q1.1 range.

Finally don't get too comfortable with the S7-200 range, it is about to be replaced by the S7-1200 range with all new software, though very similar programming method.

Bryan