S7 STL Help Please

[mrmss]

Hi,

I have never done any STL thus far but I now need to do some inderect addressing. I'm trying to write to a DB register by having a drop-down list in a HMI as the index and then some STL to use that as a pointer. The objective is to put a value from a textbox into the right register.

I started out with a FC to read from the DB and display on HMI and then a seperate FC to write to the DB from the HMI. I decided this wasnt very efficient so I've been trying to get it into just a single FC.

I have a problem with the writing bit. It just doesnt do anything! The value never gets written to the DB and the HMI flag never gets reset.

Can anyone de-bug this for me please?

  A     "dbHMItoPLC".blParamWrite// user confirms
      FP    "Tag_131"
      JNB   Label_1
      L     "almLimHiHMIindx"    // read in pointer
      SLD   5                    // Offset for real
      LAR1
      OPN   "dbAlarmLimits"
      L     "dbPLCHMI".prmAlmLmHi
      T DBD [ AR1 , P#0.0 ]      // SEND COPY OUT
Label_1 : A BR
      R     "dbHMItoPLC".blParamWrite//reset user confirm

 

[STL???]

Try this - Dont have S7 to test but should be ok

A     "dbHMItoPLC".blParamWrite// user confirms

FP    "Tag_131"        

JNB   Label_1       

L     "almLimHiHMIindx"    // read in pointer

SLD   5                    // Offset for real 

T #TempDw    // Temp Dword storage  

LAR1 #TempDw         

OPN   "dbAlarmLimits"       

L     "dbPLCHMI".prmAlmLmHi      

T DBD [ AR1 , P#0.0 ]      //  SEND COPY OUT 

CLR

 ="dbHMItoPLC".blParamWrite//reset user confirm

Label_1 : nop 0

 

[mrmss]

STL - this didnt work i'm affraid, no noticable effect.

 

[STL???]

Just noticed you open "dbAlarmLimits" then load "dbPLCHMI" changing your DB register.

try

LAR1 #TempDw          

L     "dbPLCHMI".prmAlmLmHi   

OPN   "dbAlarmLimits

T DBD [ AR1 , P#0.0 ]      //  SEND COPY OUT

 

[L D[AR2P#0.0]]

Every load/transfer like this:

L "dbPLCHMI".prmAlmLmHi

is the same as

OPN "dbPLCHMI"
L prmAlmLmHi

 

[TurpoUrpo]

Hi,

...

  A     "dbHMItoPLC".blParamWrite// user confirms
      FP    "Tag_131"
      JNB   Label_1
      L     "almLimHiHMIindx"    // read in pointer
      SLD   5                    // Offset for real
      LAR1
      OPN   "dbAlarmLimits"
      [B]L     "dbPLCHMI".prmAlmLmHi[/B]
      T DBD [ AR1 , P#0.0 ]      // SEND COPY OUT
Label_1 : A BR
      R     "dbHMItoPLC".blParamWrite//reset user confirm

This one modifies currently open DB.

 

[STL???]

Your in good hands now

TempDw isn't needed now i think more about it