triggering internal bits from a TD-200 (siemens)

[mjamil]

I'm writting a program for a packing machine.

Say from the start to the end the quantity of packs are 20, with a couple of sensors placed at say stage 3, 7, 10 etc.

I have been using the SHRB (and not shift register), under SIMATIC microwin 3.x, with a CPU-226. the SHRB is somewhat similar to shift register but most pro's use shift regs. but since the SHRB was working for me, so far I have been using it.

Now the problem is, sometimes the Machine has to be operated, after disabling any of the sensor. So far this had to be done by physically dis-connecting the sensor in question!

I am thinking of inserting a variable (say V0.0) between the INPUT and the SET instruction, so that when the bit is on the sensor work and when the BIT is OFF the sensor cannot set the bit.

I know INPUT (and output) bits can be FORCED from the TD-200, but I dont what to enable this feature at all, otherwise, this might create a mess, as enabling this option will all the user to change any input/output!

the best I could think of is, to use a byte, with a '=' comparator, so that when the byte is 0, it doesnt work, and if its anything else 1,2,3, .....100,... it works! (seems kinda weird)
The reason I think I have to use the byte instruction here, is that I dont think i've ever heard of triggering memory BITS from a TD-200.

Any comments will be appreciated.

 

[mjamil]

Here's an example of what I wanted, if any one has any ideas, please let me know.

                                                    Faulty bit

-----|   |----------|   |------------------------------( S )

   sensor 1          Vx.1                              M x.1

                                      _______

-----|   |---------------------------|       |

    packet                           | Shift |

  count pulse                M x.1 --|  Reg. |

                                    -|_______|    

Now I want to Turn ON/OF the Vx.1 bit, from the TD-200, so that when it is turned on the sensor works, and when I turn it OFF, it doesnt (no need to physically dis-connect the sensor.

now since I could'nt find out how to handle a bit from the TD200, I was thinking of using a BYTE instead, and use a comparator, here goes,

                     VB1                                Faulty bit

-----|   |----------| > | ------------------------------( S )

   sensor 1           0                                 M x.1

                                      _______

-----|   |---------------------------|       |

    packet                           | Shift |

  count pulse                M x.1 --|  Reg. |

                                    -|_______|  

Now if I replaced the value of the byte VB1 to '1' (this would do the trick) but this seems like too raw, correct me if I am wrong, and ofcourse I cannot switch to other displays, as hardware has been arranged. (but for future, projects if there is a better hardware, please point out)

 

[zottel]

Maybe you can work with the function keys. You can assign a byte in F memory in the TD200 configuration wizard, e.g. FB3. The 4 keys set the lower 4 bits F3.0, F3.1, F3.2, F3.3 and the higher bits when combined with shift, if I remember right.
I don't remember whether they are reset automatically when the key is released. I guess they are not and you have to reset them in your program.
For further details see TD200 manual.

 

[mjamil]

Thanks zottel, but I have to keep it password protected, so it has to be accesible only by the right person.