Hello,

I'm new to this field... It's hard to switch from programming to blocks environment...

I'd like to implement simple timed scenario - sequence of timed events, for instance :

set analog output 0 to 100

wait 30secs

set analog output 1 to 20

wait 10secs

set analog output 5 to 80

wait 40secs

set analog output 0 to 100

wait 30secs

...

On higher level, I'd like to have random selection among different time scenarios like above...

Can anyone help with advice or example diagram ?

Thanks.

Coming from computer programming it's often difficult to "think" in FBD or Ladder type programming methods, atleast I had the same questions when I started. 

For the specific question you asked, I would use a series of on-delay timers, partial solution below:

Another useful structure for many things is to have latching relays for each step:

ilmarix

Coming from computer programming it's often difficult to "think" in FBD or Ladder type programming methods, atleast I had the same questions when I started. 

For the specific question you asked, I would use a series of on-delay timers, partial solution below:

Another useful structure for many things is to have latching relays for each step:

 Thanks for help, now I see... Will try to do it.

[snip]

regards.

New question published by bulek is split to a separate thread with the subject How can write to analog output from several places?.

Best regards
Jen_Moderator

 Hello,

thanks for help. You gave me a basic idea.... 

I have this now in my current solution...

Can it be implemented with lower number of blocks ?

I'd also like to upgrade it, so it will repeat all the time and give me a signal, when scenario ends.

Any advice ?

bulek

 

ilmarix

Coming from computer programming it's often difficult to "think" in FBD or Ladder type programming methods, atleast I had the same questions when I started. 

For the specific question you asked, I would use a series of on-delay timers, partial solution below:

Another useful structure for many things is to have latching relays for each step:

 Thanks for help, now I see... Will try to do it.

[snip]

regards.

Hello,

made some progress. Have created 16 state machine, each state with settable duration in seconds.

In each state, custom value is on analog outputs. 

State machine cycles from last state back to first one, as long as enable signal is on.

Also, trigger happens when Enable goes to 1. 

Have I done this right ? Can it be done more optimal (less blocks) ?

I still don't now if I can implement 2-stage analog MUXes in more optimal way and with UDF ?

Thanks in advance,

regards.

ixo65

As I wrote in other topic:

Your program doesn't run in a real LOGO!. You have open outputs at some analog blocks.

This is wrong:

This were right:

 Hello,

thanks for help... This is something that I don't understand completely.

When I'm trying to connect output of Analog MUX to another Analog MUX (to gain 16:1 analog MUX overall from 4 AMUXes to final AMUX), it doesn't work to connect real outputs to inputs of the final AMUX. It works only if I connect output from parameters "Aq" to input in parameters of the final AMUX P1. 

This way works in normal FBD circuit.

Is this not the right way?

Will it not work in real Logo (I have only access to simulator) ?

Thanks in advance,

regards.

Hello,

have found the solution for the repeat of the state machine.

I simply rerouted last state output signal (goes to 1 and then to zero, when last state ends) and this triggers the first state and repeats all the states again....

Still not sure how to implement random choice between several such state machines... 

So to put a trigger in randomly chosen state machine (e.g one of four possible state machines)...

Thanks,

regards.

 Hello,

thanks for this explanation. 

Obviously I understood wrong help content regarding Analog MUX (attachment).

It says that values of V1-V4 can be provided by the value of another Analog Multiplexer.

But according to you explanation this is only possible by reference connections that will not work in real Logo (I cannot afford to connect to real analog outputs because I'll run out of those).

So in consequence, it is not possible to connect outputs of 4 analog MUXes to one second stage analog MUX to get 16:1 Analog MUX functionality without taking almost all resources on one LOGO device ?

So I'd kindly ask for more guidance or assesment whether this is possible to implement the task in the first post in this topic. If I understand right, this is too complex task to be implemented in Logo and FBD ?

So summarize;  I have 7 analog outputs and 16-32 state machine, with incremental progression between states (each state duration being settable in seconds), where I change on or more values on analog outputs... Is this possible to implement in this environment ?

If yes, please give me a hint how to approach that analog outputs changing implementation...

Is it possible to have 7 analog outputs, each with 16:1 analog mux devices ? It seems not according to new informations...

Thanks in advance for great help,

regards.

ixo65

 

bulek

Hello,

thanks for help... This is something that I don't understand completely.

When I'm trying to connect output of Analog MUX to another Analog MUX (to gain 16:1 analog MUX overall from 4 AMUXes to final AMUX), it doesn't work to connect real outputs to inputs of the final AMUX. It works only if I connect output from parameters "Aq" to input in parameters of the final AMUX P1. 

This way works in normal FBD circuit.

Is this not the right way?

Will it not work in real Logo (I have only access to simulator) ?

Thanks in advance,

regards.

That are 3 different connections.

1.) Digital connection, thin lines.

2.) Analog connections, thick lines.

3.) Reference connections, from parameter to parameter.

4.) If block outputs are open, then runs the program only in simulation, but not in e real LOGO!.
4.1) The output of a digital block must be connected
- to the digital input of a other block.
- or to a digital output.
- or to a digital flag.
- or to a open connector.
Exceptions: Digital outputs and digital flags.
4.2) The output of a anlag block must be connected
- to the analog input of a other block.
- or to a analog output.
- or to a analog flag.
Exceptions: Analog outputs and analog flags.
4.3) If you not done this, then is a program transfer to a real LOGO! not possible and LSC gives a error message. The error message can you see in the info window.

 Hello,

thanks for hint. I understood that I could solve this problem by blindly connecting each output to analog flag. But in my case I'll run out of analog flags, because I'd like to replicate this structure for 7 analog outputs...

Is my understanding correct ?

Thanks.

ixo65

 

ixo65

4.2) The output of a anlag block must be connected
- to the analog input of a other block.
- or to a analog output.
- or to a analog flag.
Exceptions: Analog outputs and analog flags.
4.3) If you not done this, then is a program transfer to a real LOGO! not possible and LSC gives a error message. The error message can you see in the info window.

 

thanks for tricks,

happy to read about them. They will save my resources...

I'd kindly ask if you can take a look at my plan and give advice, whether it is feasible.

I'm trying to implement 16 time points (as states in my state machine), for each state I can set duration in seconds. I already have this done. Out of this stage I get 4 bits that describe state number (0-15).

In each such state, I'd like to determine (predefine) analog value that will be outputted to each of 7 analog outputs.

Currently, I'm implementing this with those two stages structure of 4 AMUXes connected to final AMUX that give me 16:1 analog MUX functionality I need for each analog output. Therefore, I'll replicate this structure for each output and set values individually (according to attached matrix).

Is my aproach reasonable, or is there better approach with lower consumption of block resources ?

if I understand right, you just gave me a trick, that will allow me not to use analog flags for dummy connections of AMUX outputs, which will make circuit resilient to analog flags restriction.

If I get this right, if I connect all AMUX outputs according to your trick, my circuit should work also on real LOGO ?

Thanks in advance, your help is appreciated,

regards.

 Hello,

thanks for response, now I understand the limitations of UDF. I've already suspected that this is so, therefore I'm using Analog MUXes as normal FBD elements, without grouping them in UDF elements... I can set Vx parameters for each of them in normal FBD circuit...

The problem is also, that I dont' know how to connect properly Parameter outputs from UFD to final AMUX. I can do this in FBD circuit (from 4 aMUXes to final AMUX), but seems impossible to have one AMUX in UFD and another one in FBD, or am I wrong ?

If I connect Aq to UDF output, it says "Incompatible"...

I'm attaching my current circuit. I'm most uncertaint about that 2-stage AMUX  16:1 implementation.

If I got your advices right, I can use ACOMP + open connecter instead of analog flags if necessary.

Is there any other potential problem with running such circuit on real LOGO? 

Are reference connections ok, as long as all outputs of AMUXes are connected ?

Thanks in advance,

regards.

ixo65

In a UDF you can define only 8 UDF parameters, not 16. With the UDF parameters you can set different values for different UDFs.

bulek

Hello,

I'm new to this field... It's hard to switch from programming to blocks environment...

I'd like to implement simple timed scenario - sequence of timed events, for instance :

 

set analog output 0 to 100

wait 30secs

set analog output 1 to 20

wait 10secs

set analog output 5 to 80

wait 40secs

set analog output 0 to 100

wait 30secs

...

 

On higher level, I'd like to have random selection among different time scenarios like above...

Can anyone help with advice or example diagram ?

Thanks.

Hello.

Something bothers me.
This application is not 'simple'.

+ Which application problem are you aiming to solve?
+ How many I/O would you want to use?
+ Why are you using a LOGO! programmable relay?

A easier solution might come forward if we knew what type of application you are building. Connectivity to a PC may also be an option to provide the 'randomness'.

~

qwazee

 

bulek

Hello,

I'm new to this field... It's hard to switch from programming to blocks environment...

I'd like to implement simple timed scenario - sequence of timed events, for instance :

 

set analog output 0 to 100

wait 30secs

set analog output 1 to 20

wait 10secs

set analog output 5 to 80

wait 40secs

set analog output 0 to 100

wait 30secs

...

 

On higher level, I'd like to have random selection among different time scenarios like above...

Can anyone help with advice or example diagram ?

Thanks.

Hello.

Something bothers me.
This application is not 'simple'.

+ Which application problem are you aiming to solve?

+ How many I/O would you want to use?
+ Why are you using a LOGO! programmable relay?

A easier solution might come forward if we knew what type of application you are building. Connectivity to a PC may also be an option to provide the 'randomness'.

~

Hello,

I'm trying to establish and estimate with simulator whether this application could be implemented using LOGO!...

I have 7 analog outputs (freq. controlled water pumps) and would like to create scene with 16 (yet better 32 states), where for each I could set time duration in seconds and values for all 7 analog outputs. 

For now, it seems 16 states are feasible, maybe I can reach 32 states. The upper half of test circuit for simulation is attached to previous post. For now, only 1 scenario and no randomness of selection is in example (it seems not possible to have more than one such scenario). Connection to PC is not possible.

Since I'm novice to LOGO! and I am more used to structured text, FBD seems a but tougher to get familiar with.

I'd really appreciate a word of advice or opinion from more experienced developers.

Thanks in advance,

regards.

bulek

Hello,

I'm trying to establish and estimate with simulator whether this application could be implemented using LOGO!...

I have 7 analog outputs (freq. controlled water pumps) and would like to create scene with 16 (yet better 32 states), where for each I could set time duration in seconds and values for all 7 analog outputs. 

For now, it seems 16 states are feasible, maybe I can reach 32 states. The upper half of test circuit for simulation is attached to previous post. For now, only 1 scenario and no randomness of selection is in example (it seems not possible to have more than one such scenario). Connection to PC is not possible.

Since I'm novice to LOGO! and I am more used to structured text, FBD seems a but tougher to get familiar with.

I'd really appreciate a word of advice or opinion from more experienced developers.

Thanks in advance,

regards.

Hello.

What I hear is the method you are thinking of using to solve a problem. I am not hearing what the application actually is. This sounds like scheduled irrigation. 

You do know that the LOGO! has a limitation of how many I/O of a kind it can handle? The version of the LOGO! will determine what that limit is. Best to consult the system manual. LOGO! V8.3 can handle 8 analog outputs.

Consider also that ModbusTCP is available on LOGO! V8.3 which may be preferable instead of using analogs. LOGO! devices can also be networked to each other which open the possibility to have smaller modules installing at local sites.

You better watch for memory usage. Using UDFs has no memory usage advantage. There is a limitation to how long a string of instructions can be. Press the F2 button to 'compile' your project and get information of resources available vs used. 

My guessing is that you are aiming higher than what the LOGO! can deliver -- there are too many setpoints available. This will make the system difficult to configure for a user. The situation changes if you are the user.

I do not yet have a suggestion to handle the "lookup" of different pump setpoints, but I think the solution lies in using the shift register to trigger setpoints with calculation blocks.

 Wow, thanks for the example.

Will analyze it and learn from it. And maybe ask few questions

Regards.

ixo65

Here's a example for 16 scenarios with UDFs.

For every analog output you need 2 UDFs, total 14 UDFs for 7 analog outputs. In every UDF you can change 8 parameter values.
Double click on the UDF opens the parameter table of the UDF.

In the screenshot you see how many blocks uses the program etc..

@bulek:

Does each of the analog outputs need to have its own 16 (32) schedules?

Keep in mind that the analog outputs are sold in modules with 2 analog outputs.

qwazee

@bulek:

Does each of the analog outputs need to have its own 16 (32) schedules?

Keep in mind that the analog outputs are sold in modules with 2 analog outputs.

 Hello,

yes, it is basically a water scene with 7 pumps being regulated with analog outputs and we plan to have 8 analog outputs in hw.

I agree that part for defining analog values for each state is the biggest part of the circuit, But I see no other better way of doing it.

Regards.