Allen Bradley BSL Instruction

[93lt1]

If you don't understand an instruction, the best thing
you can do is to try it out. If this is out of question
because you don't have the PLC at hand, don't use that
instruction and make your own logic.

I like it when we get a "How does this instruction work?" type question. I learn something every time one comes up.

Well first of all, your bit_0 is on the wrong side
just as 652 is not "two hundred and fifty six".

What??



And Ron Beaufort-
I looked at it again and again thinking I was missing something!

 

[Eric Nelson]

What??

Panic was just referring to how Andrew expressed his word in the first post...

                       ________________________________________

Word B3:10            |Bit | 0 | 1 | 2 | 3 | 4 | 5 | 6 | etc-> | 

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

It's normally draw with bit 15 on the left, working down to 0 on the right. I realize what you meant Panic, but the statement 652 is not "two hundred and fifty six" should probably be 652 is not "two thousand, five hundred and sizty"

Use Panic's 0652 (HEX) example... If you place it under Andrews layout

 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15

 \---------/ \---------/ \---------/ \---------/

      0           6           5           2

The PLC will see it as 2560...

beerchug

-Eric

 

[Andrew Evenson]

Finally get to respond...!!

Hi all,

Sorry it has taken me so long to respond. I tried many times this morning, but was pulled away..anyways...to clarify some things...

I made a mistake on the timer, it IS a 0.01 time base, and a 1 preset, so it is a 10 mS timer, NOT a 1mS timer..I agree, that would be fast!!! I must have interpurted it wrong yesterday.

Eric and Panic Mode:

Yes, I had the binary representaion the B3:10 BACKWARDS!!! I just wasnt thinking yesterday..!!

It should have read...

Word B3:10            |<--etc | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Bits | 

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

Shift 1:                        0   0   0   0   0   0   1

Shift 2:                        0   0   0   0   0   1   0

Shift 3:                        0   0   0   0   1   0   0

Shift 4:                        0   0   0   1   0   0   0

Shift 5:                        0   0   1   0   0   0   0

Shift 6:                        0   0   0   0   0   0   1

Shift 7:                        0   0   0   0   0   1   0

Shift 8:                        0   0   0   0   1   0   0

Shift 9:                        0   0   0   1   0   0   0

Shift 10:                       0   0   1   0   0   0   0

BITS 6-15 are "Dont Care's"


Panic Mode:

I agree with you on testing out instructions, I had tried testing BSL out before posted, but was still having some trouble, so I posted a question!!!

As for what my logic has turned out like, here it is....

Initiate word with bits to be to be shifted on first scan.... 

    S1:15                      ----MOV---------------------- 

-----| |-----------------------| Move                      |

      1                        |                           | 

                               |Source A : 1               |

                               |Destination : B3:10        |

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

Bit Shift Timer....

 

   T65:0                       ----TON----------------------

-----|/|-----------------------| Timer ON Delay            |-(EN)

     DN                        |                           | 

                               |Timer : T65:0              |-(DN)

                               |Time Base : 0.01           |

                               |Preset : 50                |

                               |Accum :  0                 |

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



Shift Bits Left.....





   T4:65                        ----BSL----------------------

-----| |-----------------------| Bit Shift Left            |-(EN)

      DN                       |                           | 

                               |File : #B3:10              |-(DN)

                               |Control : R6:0             |

                               |Bit Address: B3:11/0       |

                               |Length:  1                 |

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



Reset(Re-Seed) Bit Shift Left Instruction .... 

    B3:10                      ----MOV---------------------- 

-----| |-----------------------| Move                      |

      4                        |                           | 

                               |Source A : 1               |

                               |Destination : B3:10        |

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

This seems to do exactly what I want..so if it works, then I'll try it..

Alternativly, this works too, as posted by 93lt1

 



Initiate word with bits to be to be shifted on first scan.... 

    S1:15                      ----MOV---------------------- 

-----| |-----------------------| Move                      |

      1                        |                           | 

                               |Source A : 1               |

                               |Destination : B3:10        |

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

Bit Shift Timer....

 

   T65:0                       ----TON----------------------

-----|/|-----------------------| Timer ON Delay            |-(EN)

     DN                        |                           | 

                               |Timer : T65:0              |-(DN)

                               |Time Base : 0.01           |

                               |Preset : 50                |

                               |Accum :  0                 |

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



Shift Bits Left.....





   T4:65                        ----BSL----------------------

-----| |-----------------------| Bit Shift Left            |-(EN)

      DN                       |                           | 

                               |File : #B3:10              |-(DN)

                               |Control : R6:0             |

                               |Bit Address: B3:10/4       |

                               |Length:  1                 |

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

Again, thanks for all your help. I appreciate ALL your tips, comments.

Andrew Evenson