New to PLCs - Step 5

[trybeforeyoubuy]

Hello all,

I'm very new to PLCs and I'm basically teaching myself a bit now I've started my first job since graduating.

I'm using Step 5 on a S5-100U PLC programme and have come across some formatting in the code that I haven't seen before and can't find in the manual I'm using.

Could someone tell me what the circled code means in the attached picture? Are they just comments?

The programme is written by a German company, in case that helps! Many thanks

 

[jraef]

Wow, if you are just starting out and are self-teaching, I'm not so sure that Structured Text Language is the best way to begin. That's typically used by relatively advanced programmers.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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[trybeforeyoubuy]

True, but most of this programme is in Ladder and only a few pages, mostly in the Function Blocks, that can't be displayed in anything other than STL.

In fact, why is it that some of these networks can't be displayed as ladder? Is it just because of the jumps in the code that can't be translated?

But anyway, my first question still applies - it'll be great to know how to handle that code at the bottom. Thanks!

 

[jjmoab]

What you can see are just the I/O pins of a function block defined by the user.

Somewhere in the code you should find that block definition, including all commands used for this particular block

 

[Tonn]

FB251 is a analog output functionblock
XE: analog value to be output
BG: Slot adres
KNKT: Channel number Channel type
OGR: Upper limit of the output value
UGR: Lower limit of the output value
FEH: Error in limit value setting
BU: Input value exceeds UGR or OGR