Help for explain of S7-300 Program example

OPN DB 36
L #IN0 // Constant number of drive
L 12
*I
+ 8
SLD 3
LAR1
L DBW [AR1,P#10.0]
T #TEMP2 // profibus address of drive
L DBW [AR1,P#6.0]
+ 26
T MW 210
LAR1 P##TEMP1
L W#16#1002
T LW [AR1,P#0.0]
L 12
T LW [AR1,P#2.0]
L 37
T LW [AR1,P#4.0]
L MW 210
SLD 3
L DW#16#84000000
OD
T LD [AR1,P#6.0]
CALL "DPWR_DAT" //SFC15 write consistent data to a DP standard slave)
LADDR :=#TEMP2
RECORD :=#TEMP1
RET_VAL:=#TEMP3
BE
This program controlling a drive on DP but I could not understand how is working?Because drive (siemens masterdrive)are ready for operate and setpoint giving but it is not operating.Thanks in advance.

OPN DB 36
L #IN0 // Constant number of drive
L 12
*I
+ 8
SLD 3
LAR1

This loads the start address of the data for a drive into AR1. Each Drive has a 12 byte data area in DB36.

INO Start Address
0 8
1 20
2 32... etc


L DBW [AR1,P#10.0]
T #TEMP2 // profibus address of drive

The 10th and 11th bytes form a word which contains the profibus address. (eg INO=1, address of word = DB36.DBW30)

L DBW [AR1,P#6.0]
+ 26
T MW 210

26 is added to contents of word address off set by 6 bytes (eg INO=1, address of word = DB36.DBW26) and stored in MW210.

LAR1 P##TEMP1
L W#16#1002 // S7 Format type BYTE
T LW [AR1,P#0.0]
L 12 // Length = 12
T LW [AR1,P#2.0]
L 37 // DB = 37
T LW [AR1,P#4.0]
L MW 210 // Contents of MW210 = word address
SLD 3
L DW#16#84000000 // Make DB Type
OD
T LD [AR1,P#6.0]

Loads a pointer to TEMP1 (a TEMP in ANY format) and an address is set up. (P#DB37.DBX[MW210].0 byte 12)

CALL "DPWR_DAT" //SFC15 write consistent data to a DP standard slave)
LADDR :=#TEMP2
RECORD :=#TEMP1
RET_VAL:=#TEMP3
BE

Then calls the DP write SFC

Peter thanks.I understand what you say except one of them.
If DB36.DBW26=60 (INT),then
L DBW [AR1,P#6.0]
+ 26
T MW 210
MW210 Then will be 60 or 86?
The other question in SFC15,RECORD :=#TEMP1 line
Can you explain this line clearly.

tulip said:

Peter thanks.I understand what you say except one of them.
If DB36.DBW26=60 (INT),then
L DBW [AR1,P#6.0]
+ 26
T MW 210
MW210 Then will be 60 or 86?
The other question in SFC15,RECORD :=#TEMP1 line
Can you explain this line clearly.

Click to expand...

First part, 86.

Second Part, RECORD is an ANY pointer to the data to be sent across Profibus.

From F1 help on SFC15

'Source area for the user data to be
written. This must be exactly as long as
you configured for the selected module
with STEP 7. Only the BYTE
data type is permitted.'

It looks like its expecting 12 bytes as that is the length hard coded.

It could be written directly, such as P#DB37.DBX86.0 BYTE 12, but as the destination is changing the ANY pointer is built for the destination.

Therefore a TEMP ANY variable which the programmer has called TEMP1 has been created and the programmer builds the source address into that ANY variable.