The "TNB" command in a PLC S5 95U. How to prepare the data correctly.

I am performing a task on a 6ES5 095-8MB04 controller. The program has two data blocks of the same length: DB13, DB14 (10 words each). It is need to copy the block 4 fields long (DW1-DW4) from DB13 to DB14.

The copy command looks like:
L<source address>
L <destination address>
TNB 8     //8 bytes, i.e. 4 words

The documentation (S5-135U CPU 928B Programming Guide C79000-G8576-C870-01) suggests the following options for preparing data for TNB:

:L RS 34 Load the base address of the DB address list
:L KB 50 Calculate the address of the entry for DB 50
: +F and load the start address in ACCU 1
:LIR 1 load start address in ACCU1

or

:L RS 34 start address of the DB address list plus 100
:ADD BN+100 produces the address list entry of DB 100
:LIR 1 start address of DB 100 (DW 0) to ACCU 1
:ADD KF+200 store address of DW 200 in DB 100 in system data

or

C DB 13
LIR 6 load contents of register DBA address DW0

I chose the following option:

:L RS 34
:ADD BN 13  //DB13
:LIR 1
:ADD KF 4 //DW4 in DB13
:T FW 130 //save DB13DW4 address in FW130
:
:L RS 34
:ADD BN 14 //DB14
:LIR 1
:ADD KF 4 //DW4 to DB14
:T FW 132 //save DB14DW4 address in FW132
:
:L FW 130
:L FW 132
:TNB 8      // copy 4 data words

After executing the code above placed in the body of the called function, all data words in DB14 are empty (zero). I tried several variants of data preparation. All of them fail.
What did I do wrong? Please.

This small “puzzle” is just a simplified version of what I really need to do - as an example for a training. What I really need is a implement copying the HMI_RECEIVE block (DB13) to the receiving mailbox DB14 (receives data over the L2 network), so that to replace the control commands that the PLC received from another PLC, with the same commands, but already receive by direct connection to the HMI station now. And there are more than 100 fields ).

Of course, this task can be done differently - using fields copy between data blocks through indirect addressing in a loop. But, I think, for the first time it will be useful to implement two options, if possible.

So…

According to S5 95U documentation, DB blocks use addresses 7E00h-7FFFh.
Therefore DB13 is located at: 13 (dec) = D (hex) => D*2 + 7E00 = 7E1A
DB14 is located at: 14 (dec) = E (hex) => E*2 + 7E00 = 7E1C

Next, I tried to focus on the example of the current code from my program (with original comments). This is the so-called service block, which implements access to any cell of the PLC through the IO server installed on the PC station via the FDL PLC-to-PLC protocol. It just uses direct access to memory addresses.

M003 :L KH 7E00 Load Start of DB Address List
:L FW 200 Load Data Block Number
:SLW 1 Multiply by 2 to Get Address
:+F
:LIR 0 Get Address of DB

---------------------

:L FW 208 Load Starting Addr of X-FER
:ADD KF 199 Point to End of 200 Byte X-FER
:T FW 208 Save Back to Flag
:
:L KH 7E80 Load Pointer to DB64 Address
:LIR 0 Get Starting Address of DB64
:T FW 210 Save Starting Address of DB64
:ADD KF 199 Point to End of 200 Byte X-FER
:T FW 210 Save it Back Again
:
:L    FW 208                              Load Source Data Address
:L    FW 210                              Load Destination Data Address
:TNB  200                                 Do 200 Byte Transfer (100 Words)

--------------------------

And my new version looks like this:

:L KH 7E1A
:LIR0
:T FW 130
:ADD KF 4     //DB13DW4
:T FW 130
:
:L KH 7E1C
:LIR0
:T FW 132
:ADD KF 4      //DB14DW4
:T FW 132
:
:L FW 130
:L FW 132
:TNB 8
:BE

The DB 4 is still empty, unfortunately

Take care :

DW's are in word. I can't Remember if the first one is DL0 or DR0.

But I think if you use ADD Kf 4, you only increase of 2 DW only.

Best regard.

I suspect that you should open the source and target DB-s before you can transfer from one DB to another. Years back when I did S5 i copied db-s like this:

Calcululate start adress of the source DB and save it to Adress register 1

Calcululate start adress of the target DB and save it to Adress register 2

open source DB

Load word with indirect read using AR1 (or even Load doubleword if the copy amount allows it)

open Target DB

Save with indirect write using AR2

Increase AR1 and AR2 with appropriate amount (depends if you copy bytes, words or doubles) and also increase "amount transferred "

if all transfers not done jump back to "open source DB"