S7 - BLKMOV With Area Crossing Pointers

pethoek · Jan 26, 2011

In my project i use an Anybus-X gateway for exchanging data with 3rd party as a modbus slave.

Data is provided as means of PIW and PQW area and in order to used separate bits in a word i ned to somehow copy the word from PIW area to in my case a structure in a DB.

Totally i need to copy 20 bytes from PIW to my DB-Struct.

I have used any pointers before, but not so much that i can say i'm comfortable with the concept. So instead of just asking you guys of a solution, i tried to come up with one myself.

So please could anyone tell me if this will work or not.

Purpose: Copy X Bytes from PIW-area to DB-Area

Network 1

Code:

     LAR1  P##anySrc
      L     W#16#1002
      T     W [AR1,P#0.0]               // 10h for S7, 02 for BYTE
      L     #Bytes
      T     W [AR1,P#2.0]               // Repetition fctr 
      L     W#16#0
      T     W [AR1,P#4.0]               // Not a DB
      L     W#16#8000
      T     W [AR1,P#6.0]               // P-Area
      L     #Laddr                      // P-Adress to start copying from
      SLD   3                           // Byte.Bit convertion
      T     W [AR1,P#8.0]               // Byte.Bit

Network 2

Code:

      LAR1  P##anyDest
      L     W#16#1002
      T     W [AR1,P#0.0]               // 10h for S7, 02 for BYTE
      L     #Bytes
      T     W [AR1,P#2.0]               // Repetition fctr
      L     DBNO
      T     W [AR1,P#4.0]               // DB number
      L     W#16#8400
      T     W [AR1,P#6.0]               // DB-Area
      L     #DBB                        // Byte adress to start pasting
      SLD   3                           // Byte.Bit convertion
      T     W [AR1,P#8.0]               // Byte.Bit

Network 3

Code:

      CALL  "BLKMOV"
      SRCBLK :=#anySrc
      RET_VAL:=#retVal
      DSTBLK :=#anyDest

Best regards
Pethoek

TurpoUrpo · Jan 26, 2011

Is there reason for you not to try it in simulator?

KalleOlsen · Jan 26, 2011

This is from the SFC20 help text:

Description
You use SFC 20 "BLKMOV" (block move) to copy the contents of a memory area (= source area) to another memory area (= destination area).
Permissible source areas are the following:
· Parts of data blocks
· Memory bits
· Process-image partition (part process image) for inputs
· Process-image partition (part process image) for outputs
The source parameter can be a part of the data block in the load memory which is not relevant to program execution (DB compiled with the keyword UNLINKED).

Note that the P-area is not defined as process image (only I and Q are). So I would be very supprised if this will work.

I recon you will have to make a load/transfer loop in stead.

Kalle

JesperMP · Jan 26, 2011

The anybus device is probably on profibus, right ?

In that case, and you use the integral DP port in the CPU, you must use SFC14 and SFC15 to get the data from the PIW and PQW areas to and from your DB.
Or, if it is via a CP342-5, you have to use DP_SEND and DP_RECV blocks.

pethoek · Jan 26, 2011

The Anybus is on Profinet so i only have to set it up correct in HW-Config.

Ok, so BLKMOV won't do it. OK, well, I'll do it the "hard" way then instead of using a dynamic function. Time is time, and time equals money so thanks for your suggestions.

By the way, congrats to the victory in last nights game

(Handbolls-VM)

pethoek · Jan 26, 2011

TurpoUrpo said:
Is there reason for you not to try it in simulator?

Yes there is a reason, haven't got PLCSIM...

JesperMP · Jan 26, 2011

SFC14 and SFC15 also work with an integral Profinet port.
Even if they are named DPRD_DAT and DPWR_DAT.

Tack så mycket for komplimenten.

pethoek · Jan 26, 2011

TurpoUrpo said:
Is there reason for you not to try it in simulator?

JesperMP said:
SFC14 and SFC15 also work with an integral Profinet port.
Even if they are named DPRD_DAT and DPWR_DAT.

Tack så mycket for komplimenten.

But there is no need for them. I tested to write the Clock-Memorybyte to a PQW address, and on the other end of the modbus network i had an ABC Communicatior set up, and when i turned on the monitor mode i could se the clockbyte nicely counting.

TurpoUrpo · Jan 26, 2011

No need, but u can write(/read) more than 4 bytes consistently with those sfc's.

S7 - BLKMOV With Area Crossing Pointers

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