Does anyone use instruction list?

Are there any Pros?

It feels like using an old HP calculator

Good ol reverse Polish notation in those hp's....

Honestly, most of the pros for using IL are implementation based. In an S7 300/400 (and maybe older?), IL/STL/AWL is pretty much how the processor thinks. It did all possible functions. There were a lot of features that never made it to their LAD editor, like indirect addressing. Germans tend to love it, and it was the cheapest (SCL is a paid option in Simatic manager) and fastest way to program indirect addressing. A "Real Programmers use STL" attitude developed, and it held them back from adding a lot of features to LAD, like indirect addressing/pointers. Some used it because they liked it, some used it because they had to. Programmers liked the power/capability, but I think many of them would have used another language if they could have.

I'm in the "have to" pile. I would only use IL if I needed advanced functions, and the customer refused to permit SCL. If the processor allows for indirect addressing in LAD (Rockwell, newer siemens processors, etc), there is really no NEED to use it. It is less readable than SCL if you want to do text based, and is considered depreciated in the most recent IEC 61131 revision.

The only positive I really have for IL is that it was a compact way to set/reset a lot of bits. Again though, this was more of a system implementation limitation than a feature of the language.

Also, you remember how well your last programming language thread went. Do you just like to start flame wars on the Internet?

Some men just like to watch the world burn....

I think I had to use it once to do can open in a twido

mk42 said:

Also, you remember how well your last programming language thread went. Do you just like to start flame wars on the Internet?

Some men just like to watch the world burn....

Click to expand...

fair enough, but I blame myself for how that ended.

I get stoned and feel paranoid that there is something I don't know out there.

Like this whole embedded processor community and the like.

ganutenator said:

It feels like using an old HP calculator

Click to expand...

There are those of us that grew up using HP RPN calculators and feel awkward with anything else ;-)

I guarantee you that there is TONS you don't know out there. This time though, I wouldn't say you're missing much.

Dear Sir,

In Twido plc I have to give time to timer from how to assign a tag and memory address to enter the timer value

In Twido PLC I have to give time to timer from HMI how to assign a tag and memory address to enter the timer value

yes i do use it in interupts to be fast.

shooter said:

yes i do use it in interupts to be fast.

Click to expand...

The fact that it is fast is purely implementation dependent, though. In an S7-300, the processor pretty much thinks directly in STL, and as such all other languages get compiled directly to it. This makes STL faster.

In most other PLCs, however, STL/IL doesn't work that way. From Siemens, the newer 1500's actually have to have an emulation layer to pretend that the accumulators exist, so that the STL can be executed, and it is slower than simply doing everything in LAD. I'm sure most American PLCs have to do something similar, if they even support IL at all.

actually, this old direct logix program turns into instruction list w/ a click of a button.

If I knew a way to write a pearl script, I could import this easily.