Telemecanique - TSX17 - Tasks

[rlmts]

Hi!

Before I post too much detail... is anyone familiar with the programming structure of TSX17 programs?

I have a print-out of the 'ladder' and it appears to be segregated into 'tasks'...

FAST
MASTER/PRL
CHART
MASTER/POST

I also need to understand the Fast Counter, and it's relationship to the task called 'FAST' The PLC has an encoder connected to it's dedicated connection, which I believe drives the Fast Counter (FC31?) There is no user comments etc so I'm not clear what it's doing yet.

I am required to convert to AB Micrologix.

Any help / comments appreciated.

I'll leave it at that for now!

Rich

[Jim Dungar]

Originally Posted by rlmts

Hi!

Before I post too much detail... is anyone familiar with the programming structure of TSX17 programs?

I have a print-out of the 'ladder' and it appears to be segregated into 'tasks'...

FAST
MASTER/PRL
CHART
MASTER/POST

I also need to understand the Fast Counter, and it's relationship to the task called 'FAST' The PLC has an encoder connected to it's dedicated connection, which I believe drives the Fast Counter (FC31?) There is no user comments etc so I'm not clear what it's doing yet.

I am required to convert to AB Micrologix.

Any help / comments appreciated.

I'll leave it at that for now!

Rich

Good luck.

Your TSX17 is programmed in a Sequential Flow Chart (SFC) style of programming.

FAST is a subroutine that is called on a time basis. This timed execution allows you to predict when this logic will be executed rather than having it change with based on scan time (which can really vary with SFC). Tasks that are time dependent should be located in this area even if they are not "FAST".

MASTER/PRL is a portion of the program that is always scan prior to executing the SFC it often contains interlocks and permissives but, it can be left empty.

CHART is the actual SFC program

MASTER/POST is the portion of the program that is always scanned after the SFC. This area usually contains the actual "output" coils which are controlled by step bits from inside the SFC. Many times the interlocks are included in this section because it is programmed in ladder logic.

[rlmts]

Thanks Jim!

Very enlightening.

What does anyone know about the 'Fast Counter'? (FC31)

Rich

[rlmts]

Oh dear! Not much known about this issue then?
That's reassuring! Shall I shoot myself now <LOL>
Rich.

[krk]

Found this in the manual...don't know if it's what you're looking for though:

[rlmts]

Thanks KRK that looks very useful, will study that.

Here's a section of the code I have to convert, it's to do with the Fast Counter, any comments regarding anything anyone recognises in there will be very welcome!

Theres also a small Fast Task to do with it.

Rich

[rlmts]

By the way KRK, is that a complete TSX17 manual you have there?
Rich.

[krk]

Its from the PL7-2 V5 languages reference manual which can be found towards the bottom of this page:

PL7 Software Documentation


Other random TSX17 documentation can be found here:

TSX 17 Technical Documentation

[rlmts]

Thanks krk, those links are very helpful.
Any comments on the posted code anyone?
Rich

[rlmts]

Even with the helpful links from KRK I am struggling to find the wiring information for the I/O Extension Rack TSX DMF 342A Does anyone have a drawing and specs for this please? I believe it's 22 inputs and 12 relay outputs.

[504bloke]

Originally Posted by rlmts

Even with the helpful links from KRK I am struggling to find the wiring information for the I/O Extension Rack TSX DMF 342A Does anyone have a drawing and specs for this please? I believe it's 22 inputs and 12 relay outputs.

This may help

[rlmts]

Originally Posted by 504bloke

This may help

Thanks Dave, I had actually looked at that one before, and assumed there would be something else somewhere that showed a connections drawing for the TSX DMS 342A Extension unit.

Although it is mentioned in the 'specs' there appears to be no drawing for it?

Must assume it is the same as this connection drawing towards the end of the document...

TSX 172 2028/172 3428 PLCs
c 110…240 V power supply, 12 (or 22) a 24 V isolated inputs, 8 (or 12) relay outputs

Will have to visit plant again and have a better look!

Rich

[krk]

Rich,

Had a (very) quick look at your posted code and have a couple of comments.

(Bear in mind that although I worked on a lot of TSX systems in the 80's I haven't done much with them since.)

Originally Posted by Jim Dungar

FAST is a subroutine that is called on a time basis. This timed execution allows you to predict when this logic will be executed rather than having it change with based on scan time (which can really vary with SFC). Tasks that are time dependent should be located in this area even if they are not "FAST".

On any other TSX system Jim would be correct as the Fast Task was a synchronous periodic task with them, however with the TSX17-20 you have to work with, the Fast Task is event driven. In your case it will be executed when the fast counter (FC) actual value reaches the current preset value (FC,V = FC,P). The actual value FC,V is also reset by the system at this point.

It's difficult to reverse engineer this type of thing knowing absolutely nothing about the process it's controlling so the following comments are mostly WAG's....

* In Labels 110 to 112, W8 is compared to constant values which are 2x, 1x and 0x (well <1) the maximum theoretical count value, this in turn writes a corresponding value of 2, 1 or 0 to W10. Is the fast counter wired to an encoder?

* The first rung of Label 150 and Labels 160 to Label 191 are not relevant to the fast counter code. These look to be generating various fault codes which are then converted to ASCII, embedded in a string and squirted out of the programming port to some peripheral device - a display or a serial printer maybe?


Kevin H

[rlmts]

Thanks Kevin.

Yes, the Fast Counter is connected to an encoder, which is mounted on the wheel of a crane that taverses to numerous stacking positions where it lifts or lowers product, the encoder is 200 Impulses/Rev and I believe direct driven on a 12" dia traverse wheel (size guessed from brief visit at the moment!)

As for the other code which you mentioned as not relevent to the counter, yes, there is an XBT A801010 Telemec HMI on board, where I'm told they can preset a retrieval and stacking positions sequence for the product.

There is no documentation for any of the Telemec gear PLC / HMI ! So struggling a bit.

Thanks,
Rich.

[rlmts]

Without the original supporting docs, is it possible to establish which PLC memory locations the XBT HMI writes to?

Also, the TSX 17 has it's 'Fast Inputs' 24 and 25 connected, I read that if one of these changes state, this also 'calls' the 'FAST' task. Is this correct? I am confused about the fact that the Fast Counter also 'calls' the same FAST task. There's not much code programmed in this FAST code (see previous post attachment)

There was also mention in one of the Telemec documents that the 'Fast Inputs' must be configured as such? Where can this be seen to establish if they are configured as 'Fast'?

So many questions! Sorry...

Rich.