stl to lad

hi,

i am good at understanding LAD but not STL. right now i have some STL programme which i try to convert to LAD. what i don't understand is "_002 A BR,BLD 103,BLD 102" , what is the mean of the "BR". if convert to LAD what it looks like. please help me

thanks a lots

A #START_TIME
A #w1
AN #R1_RESET
= L 59.0
BLD 103
A(
A #START_TIME
A #w1
O #R1_RESET
)
JNB _002
CALL #R1_T1
IN:=L59.0
PT:=T#1H39M
Q :=
ET:=#T1
_002: A BR
= L 59.0
A L 59.0
JNB _003
L #T1
L L#10
/D
T #W1_T1
_003: NOP 0
A L 59.0
BLD 102
S #R1_W1

What kind of PLC?
What software are you using?

I see that you have a 'NOP' instruction did you write this?, if its S5 then I may be able to help...if not then someone else may, the reason I say these things...it does not look like a S5, also if it had a NOP then it may convert also there are some after market software that will convert it for you

Ill take a stab...........


Siemens PLC, Siemens Software

In not hot on Siemens or STL but...

Taken from STL for S7300 and 400

BLD Relates:
Program Display Instruction - The Instruction does not carry out any function and does not influence the status bits. The instruction is only relevant to the Programming Device (PG) when a program is displayed. The adress <number> is the id of the instruction BLD and is generated by the programming device.

A BR Relates:

To checking the status word - The 1 or 0 in bit 8 in the status word is included in a boolean logic combination

Ive attached in zip form the S7300/400 STL Manual i have.

S7STL.zip is fine
S7STL1.zip needs renaming to S7STL.z01
S7STL2.zip needs renaming to S7STL.z02
S7STL3.zip needs renaming to S7STL.z03

For winzip to unpack it correctly! Last time i tried i couldnt attach .z0x files so had to rename them to .zip

Im sure if its siemens then one of the experts here will give you more/better info!

I think you are correct Dave :nodi:


That also means I'm out...

BR is one of the bits in CPU status word. In STL it sometimes could be used by programmer as auxiliary bit for ex. storing result of binary operations. It's used to pass information about errors in execution of system and standard blocks to your program.
In the LAD and FBD you can't use BR. It's used by Step7 for passing "enable" ("power flow") through the called blocks with EN and ENO.
BLD instructions a treated by CPU like NOP's they are only for controlling of program display.

Above S7 code looks like it was switched to STL view from LAD (or FBD?). Are you sure that you cannot dispaly it in LAD or FBD? (Ctrl+1 or Ctrl+3)

If you turn type checking off, the original code displays as ladder - it is not quite the same as you have posted as the SET appears in parallel with the divide, not after it.

You're right Simon SET is in parallel to divide. My fault.
After disabling of type checking the original code could be displayed in LAD. I've deleted my last message.
I don't like LAD/FBD, especially in Siemens. I think I'm STL man.