Logix 5000 sequencer

[the_msp]

I am rolling my own sequencer in logix 5000 (v18) and have a few queries. I am using integers to represent my steps.

I have an AOI as each step at the end has a time delay, and then in the AOI there is logic to transition to the next step. Is it possible to have the AOI write to a controller or program scoped tag? If not what is the best way to advance to the next step, a ONS MOV?

 

[harryting]

I'm probably not understanding your question correctly. Of course you can move or copy the AOI's instance to another tag. The instance of the AOI itself has to be either a controller or program tag.

 

[jstolaruk]

I am rolling my own sequencer in logix 5000 (v18) and have a few queries. I am using integers to represent my steps.

I have an AOI as each step at the end has a time delay, and then in the AOI there is logic to transition to the next step. Is it possible to have the AOI write to a controller or program scoped tag? If not what is the best way to advance to the next step, a ONS MOV?

A controller or programmed scoped tag can be passed by reference in the AOI's input/output definition.

 

[mellis]

I am rolling my own sequencer in logix 5000 (v18) and have a few queries. I am using integers to represent my steps.

I have an AOI as each step at the end has a time delay, and then in the AOI there is logic to transition to the next step. Is it possible to have the AOI write to a controller or program scoped tag? If not what is the best way to advance to the next step, a ONS MOV?

Sounds like how I do sequences to some extent. I haven't found a use for an AOI for step transitions, perhaps you can elaborate on that?

My approach is:

EQU Step_No 1000 BST (actions to take in this step)
NXB (conditions to move to next step) MOV 1100 Step_No BND

If it gets complicated, you can use several rungs all with EQU Step_No 1000 at the start of the rung. Most of the time, I use one rung per step.

To advance to the next step, MOV the next step number into the Step_No tag is sufficient. The ONS isn't needed. The next scan, the rung will be false anyway due to the new step number.

 

[AGill]

Unless you specifically need the code in the AOI, abandon using them. Start simple, condition met for step x, add 1 to step, do something/fire outputs, conditions met for step x+1, add 1 to step, do something/fire outputs, and so on.

 

[the_msp]

I do apologise for not updating this thread for ages... I took onboard the advice (abandoned the AOI approach) using MOV's instead and it's working great.

My reason behind using an AOI in the 1st place; I searched on here for advice on L5K sequencers and came across several threads and got the AOI idea from this one: http://www.plctalk.net/qanda/showthread.php?p=688267#post688267

Thanks!

 

[AGill]

Cheers!