ControlLogix Addressing; New to PLC Programming Environment

[JoeTu]

This may sound like a trivial question, but please bear with me (I obvioiusly have not been programming long)!

I want to use a MOV instruction move a value of 1 into a destination bit. However, i want to address the destination bit according to the following scheme:

What is the proper way, if there is a way to address the destination bit based on the tags WordRes and BitRes?

 

[LJBMatt]

You can't use a move instruction for a address a bit. You either have to use an OTE or OTL/OTU instructions if you want to manipulate the bit.
there are other ways but this is what i know will work. Depending on whether or not you need the bit to remain "hi" in a false state will help you choose between the two ways of setting your bit.

 

[dmroeder]

"BitRes" is an array of bools?. MOV instructions are for words, not bits. Bits need to be OTE's, OTL's, OTU's, ONS ect.

I think instead of a MOV, you can change it to an OTE and use the same tag. If you want it to hold the value while the rung is not true, then make it an OTL.

 

[dmroeder]

I was slow. I got it half way typed and then got side tracked...

 

[bernie_carlton]

1. WordRes and BitRes don't need to be arrays

2. The following is accepted as an OTL address:

MsgEvent[WordRes].[BitRes]

 

[LJBMatt]

dmroeder

It looks like he is doing indirect addressing for an array of tags called MsgEvent where WordRes is the word array destination and BitRes is the bit of that Word he wants to turn on. It looks as though your indirect addressing may need some massaging as well.

 

[JoeTu]

Thank you all for the education; I will try and use the OTL and see if it works!

Thanks

Joe

 

[JoeTu]

Guys,

I am attempting to use indirect addressing, if that is the correct name for it, i was not sure. But below you will find the tag data types. I tried using the addressing for the
MsgEvent[WordRes].[BitRes] with no success; I receive the following error: Invalid array subscript specifier.

thanks

 

[bernie_carlton]

Change WordRes and BitRes from arrays to just INT

 

[dmroeder]

Ah, my suggestion won't quite work out as planned. Having arrays in indirect addresses = no dice. Bernie pointed this out in his post.

Also, I'd use DINT's if you don't have to use INT's. DINT's are supposed to process more efficiently from what I hear.

 

[JoeTu]

Bernie and DM,

Thanks for the insite; I got the code to work using an OTE and changing the data type to just an integer!

Many thanks,

Joseph