Discrete Input Interrupt Allen Bradley 5/05

[feike2]

I have another question about a DII with an Allen Bradley 5/05. I was told you can only use one DII in your program. Am I correct, or can I program more DII (Discrete Input Interrupt)? I need to read the acc. count of a 1746-HSCE at the begin en at the end of a product in hi speed (Conveyorspeed about 80 meter/minute, product widht 50 mm). So I have two trigger moments for the interrupt.

An other problem: Is the accumelated count I:e.1 of the hi speed counter 1746-HSCE up to date or must read the count value from another file word????

Can anyone please help me how I can handle this problem? Thanx

 

[Beryl]

Yes and No

True there is only one DII available but it is possible to use indirect addressing so that you can use a large number of DII's.

I don't have an example or time to write one out. Take a look at indirecting and post again if you have questions.


Beryl

 

[Doug_P]

Yes, there is only one DII. However it is extremely versatile in that up to eight input bits can be used to trigger the interrupt and they can be selected to trigger on either the leading or trailing edge.

Another aspect of the versatility of this function is that the trigger condition(s) can be modified on the fly. That is, if you want, you can set up the interrupt to trigger on the leading edge, and then in the interrupt routine, or elsewhere in the program, toggle the edge detection mask bit so the the interrupt triggers on the trailing edge. This seems like it would work to get where you're trying to go.

If you need to do different actions based on which signal gave the interrupt you can decode the return mask (S:51) and JSR to a special handler.

Check out chapter 11 of the SLC instruction set reference,
A-B pub. 1747-RM001D-EN-P - November 2003

 

[feike2]

Thanks a lot!!! I can handle the problem now! Greetz

 

[Craig Spinharney]

You can also change the file number (S:46) you want to scan when an interrupt happens and the slot number to monitor (S:47).

STI's can be managed the same way so that you can have multiple program files to use as your DII/STI although only one can be cued up as the "current" file to run upon interrupt.

Craig

 

[(8{)} ( .)]

...But whatever you do (ie. changing file numbers on the fly) document it to death...


Good Luck,

(8{)} ( .)

(Yosi)

 

[Craig Spinharney]

"...But whatever you do (ie. changing file numbers on the fly) document it to death..."

AAAAAAAAAMMMEEEEENNNNNN !!!!!

 

[davidg68124]

Is this the Craig Spinharney that works for Rockwell???? If so, I know you!!

David Gulick