s7 pointers p#

[freddofrog]

Darren, below is the source code for FC397 which shows an example of using any pointers as well as AR1 (address register 1). FC397 extracts the bit number, byte number and area type for an I, Q or M. It returns "?" if the area is not one of the above. (Other areas can be extracted, I've just not included them in this example). Also included is the source code for FC398 which calls FC397 with four different areas. If you cut/paste this into a source code file and then compile, it should generate these two blocks in your blocks folder. Call FC398 from OB1 and then monitor FC398.


FUNCTIONFC 397 : VOID
TITLE =Find byte and bit address ofI, Q, or M
VAR_INPUT
pIOAddress : ANY ;
END_VAR
VAR_OUTPUT
iByteAddress : INT ;
iBitAddress : INT ;
cAreaIQorM : CHAR ; //area I,Q or M or ?
END_VAR
BEGIN
NETWORK
TITLE =decode input pointertype and get byte/bit address
L P##pIOAddress; //point to input parameter
LAR1 ;
LB [AR1,P#6.0]; //get address area
L W#16#81; // I area ?
==I ;
JC inpu;
TAK ;
L W#16#82; // Q area ?
==I ;
JC outp;
TAK ;
L W#16#83; // M area ?
==I ;
JC mflg;
L '?'; // not any of the above
T #cAreaIQorM;
JU nof;
inpu: L 'I';
T #cAreaIQorM;
JU nof;
outp: L 'Q';
T #cAreaIQorM;
JU nof;
mflg: L 'M';
T #cAreaIQorM;
JU nof;
nof: LB [AR1,P#9.0]; //lower 3 bits of byte 9 of area is bit address
AW W#16#7;
T #iBitAddress; //bit address
LD [AR1,P#6.0];
AD DW#16#3FFFF; //mask off operand area
SRD 3; //and shift to get byte address
T #iByteAddress;
SET ; //ENO = 1
SAVE ; END_FUNCTION

FUNCTIONFC 398 : VOID
TITLE =test FC397
VERSION : 0.1

VAR_TEMP
iByteAddress : INT ;
iBitAddress : INT ;
cArea : CHAR ;
END_VAR

BEGIN
NETWORK
TITLE =call FC397 with 4 different pointers
CALLFC 397 (
pIOAddress :=I 9.3,
iByteAddress := #iByteAddress,
iBitAddress := #iBitAddress,
cAreaIQorM := #cArea);
CALLFC 397 (
pIOAddress :="IntAutoLoad",
iByteAddress := #iByteAddress,
iBitAddress := #iBitAddress,
cAreaIQorM := #cArea);
CALLFC 397 (
pIOAddress :="bBowedRollReverseQ",
iByteAddress := #iByteAddress,
iBitAddress := #iBitAddress,
cAreaIQorM := #cArea);
CALLFC 397 (
pIOAddress := DB100.DBX 30.6,
iByteAddress := #iByteAddress,
iBitAddress := #iBitAddress,
cAreaIQorM := #cArea);
END_FUNCTION

this is a poor example of pointer control. Right at the very start of the code when the address register was loaded, you should of performed a SLW 3 and started the P# pointer calls at 0.0 instead of 6.0

EG

L #VLT_ADDRESS // Load drive base address in I/O Area
SLW 3
LAR1 // Load address register AR1 with drive base address
L PIW [AR1,P#0.0] // Move Drive Status Word from I/O Area
T #VLT_STATUS // into the instance data word (ZCD_ZSW)
L PIW [AR1,P#2.0] // Move Main Actual Value from I/O Area
T #VLT_MAV // into the instance data word (PZD_HIW)
L PIW [AR1,P#4.0] // Move PCD 3 Value from I/O Area
T #VLT_PCD3 // into the instance data word (PZD_HIW)

 

[manmeetvirdi]

Hi razi

If your array for example is made up of 100 bytes then you can go like this:

L P#46.0 //#index1
LAR1 P#DBX 0.0
+AR1

L P#47.0 //#index2
LAR2 P#DBX 0.0
+AR2

L B [AR1,P#0.0]
T B [AR2,P#0.0]

this will copy 46th byte to 47th byte

 

[Thim]

What you are doing is totaly different from what Simon is doing.

this is a poor example of pointer control. Right at the very start of the code when the address register was loaded, you should of performed a SLW 3 and started the P# pointer calls at 0.0 instead of 6.0

EG

 

[PeterW]

this is a poor example of pointer control. Right at the very start of the code when the address register was loaded, you should of performed a SLW 3 and started the P# pointer calls at 0.0 instead of 6.0

EG

L #VLT_ADDRESS // Load drive base address in I/O Area
SLW 3
LAR1 // Load address register AR1 with drive base address
L PIW [AR1,P#0.0] // Move Drive Status Word from I/O Area
T #VLT_STATUS // into the instance data word (ZCD_ZSW)
L PIW [AR1,P#2.0] // Move Main Actual Value from I/O Area
T #VLT_MAV // into the instance data word (PZD_HIW)
L PIW [AR1,P#4.0] // Move PCD 3 Value from I/O Area
T #VLT_PCD3 // into the instance data word (PZD_HIW)

You have made two mistakes here.

#1

Not SLW 3 BUT SLD 3 (a mistake I sometimes make initially)


#2

You have questioned the integrity of the forums indeirect addressing god L D[AR2,P#0.0]




I also cannot understand reviving an ancient thread to critises it?

 

[Thim]

At least i tried to say it polite ;-)
But maybe Fred can show us the exact same thing like LD is doing in another way?

 

[manmeetvirdi]

#2

You have questioned the integrity of the forums indeirect addressing god L D[AR2,P#0.0]

Mistake #2 will make even the Siemens PLC go berserk !!
:skullereadly

 

[PeterW]

At least i tried to say it polite ;-)
But maybe Fred can show us the exact same thing like LD is doing in another way?

I was in a bit of a hurry and never noticed that he was doing something totally different .

freddofrog he was recovering the data area from an ANY pointer.

And sorry, I see you didn't resurect the thread, is_razi did with a question.


To answer part of is_razi's questions.

No you cannot do

L Array[#index]

at least not in STL, you can in SCL though.

If you use AR2 as suggested, then beware, if doing so in an FB then it must be saved and restored because its the pointer to the Instance DB data start area.

 

[Thim]

You have made two mistakes here.

#1

Not SLW 3 BUT SLD 3 (a mistake I sometimes make initially)

For #1 a picture says more then a 1000 words

 

[freddofrog]

You have made two mistakes here.

#1

Not SLW 3 BUT SLD 3 (a mistake I sometimes make initially)


#2

You have questioned the integrity of the forums indeirect addressing god L D[AR2,P#0.0]




I also cannot understand reviving an ancient thread to critises it?

do you mean "Criticize"?

 

[PeterW]

do you mean "Criticize"?

lol no, I'm British old chap "Criticise" is the correct correction.

 

[freddofrog]

lol no, I'm British old chap "Criticise" is the correct correction.

it was actually a joke sport, im not american either hehe