SLC Copying of Programming Steps

spencer977 · Sep 14, 2006

Hello,

I have seen that often in programms for the stepping inside the
files is done the following:

First Step

--XIC B25:1/0--------------------L-B24:1/1------

for the next stepp

--XIC B25:1/1--------------------L-B24:1/2------
------------------------|--------U-B24:1/1------|

In the main programm is one copy command that copy
all the bits from B24 to B25.

So the second step will only be done, if the slc has copied
the B24:1/1 to the B25:1/1 (inside the main file).

Is this normally for the PLC/SLC programming to do only one
step per fileat every scan of the cpu?

Is this neccessary?

rPraveenkum · Sep 14, 2006

spencer977 said:
Hello,

I have seen that often in programms for the stepping inside the
files is done the following:

First Step

--XIC B25:1/0--------------------L-B24:1/1------

for the next stepp

--XIC B25:1/1--------------------L-B24:1/2------
------------------------|--------U-B24:1/1------|

In the main programm is one copy command that copy
all the bits from B24 to B25.

So the second step will only be done, if the slc has copied
the B24:1/1 to the B25:1/1 (inside the main file).

Is this normally for the PLC/SLC programming to do only one
step per fileat every scan of the cpu?

Is this neccessary?

Instead of bitwise stepping ( 16 steps is only possible per word ) & also you cannot insert a step in the middle during debuging you have to rearrange the steps for inserting

you can use Equ & Mov per word By incrementing the word by value 10 or 5 you can easily inset a step in between.

spencer977 · Sep 15, 2006

Thats O.K. and I understand what you mean.

But this, what you said can also be done when I only have
one file (B24) for the steps.
I think I can debug my software the same way when I would
use two files for the steps.

Is there any time advantage to do this copy function, or
any cycle time advantage. ?
Greetings

averytc · Sep 15, 2006

I've done it both ways, and found incrementing a word to be easier to trouble-shoot. It's also easier to manipulate when simulating code before role-out. I can tell no difference in scan times.

Clay B. · Sep 15, 2006

I have heard this called Stable State programing. It basically works like the other posts said.

At the end of the day it is just a sequencer. I agree with others on here is that I prefer to just use a interger that I increment after I complete each step.

The integer also make for some lazy monitoring. Basicaly I watch the value in the integer and I know exactly where I stopped.

SLC Copying of Programming Steps

spencer977

Member

rPraveenkum

Member

spencer977

Member

averytc

Member

Clay B.

Lifetime Supporting Member

Similar Topics