S7 code explanation

[arocon]

Could anyone please explain me what is doing the following code:

// set BR =1
SET
SAVE

// check for a valid DB number
L 0
L #DB_Number
==I
JC DNE
T #DB_Tpen
// open block and wrtie what we need
OPN DB[#DB_Tpen]

// offset for pallet data
L #DB_Offset
SLW 3
LAR1
// the data
L #Data
T DBW[AR1,P#0.0]

DNE:BE

Thank you.

 

[cjd1965]

Hi I am no expert on stl but here goes my understanding, in red
Basically it checks a datablock number is not 0, opens it and stores data at an offset

SET
SAVE

Check that the parameter for the data block number is not 0
// check for a valid DB number
L 0
L #DB_Number
==I
If 0 the jump to done
JC DNE
not 0 so copy to variable DB_Tpen
T #DB_Tpen
// open block and wrtie what we need
Open the DB number from the parameter above
OPN DB[#DB_Tpen]

make a pointer to the given off set and store the information #data
// offset for pallet data
L #DB_Offset
SLW 3
LAR1
// the data
L #Data
T DBW[AR1,P#0.0]

DNE:BE

 

[TurpoUrpo]

It transfers what is in #Data to word defined by #DB_Offset in DB defined by #DB_Number.

Example:

If DB_Number is 3, DB_Offset is 12 and data is 456. After execution, DB3.DBW12 = 456.

You need to show whole block & how it is called for more detailed analysis.

 

[s7user]

hi,arocon
1.force ENO:=1 for your FC or fB result.
2.DB0 means no DB existing,i.e. S7 has no DB0.
3#DB_Offset occupies byte ADRRESS for **** right 3 bit.
The right 3 bits are bit address .
In Siemens S7 world bit is from 0 to 7 .Example M1.0~M1.7 for AR1/AR2 addressing.