Ladder Logic HA
- Thread starter Gearhead
- Start date
Deane Johnson
Active Member
I'm not sure it's what you have in mind, but the Ocelot uses ladder logic, programmed with their free C-Max software.
http://www.appdig.com/adicon_new/ocelot.htm
http://www.appdig.com/adicon_new/ocelot.htm
fcwilt
Active Member
Such as?
Ocelot is my first thought as well.
Ocelot's CMAX programming is a lot more flexible than the rule based systems current popular HA controllers support. I guess the BarioNet controller could also qualify, eventho it's way more powerful than the Ocelot, not sure if it is still considered ladder logic.
Ocelot's CMAX programming is a lot more flexible than the rule based systems current popular HA controllers support. I guess the BarioNet controller could also qualify, eventho it's way more powerful than the Ocelot, not sure if it is still considered ladder logic.
BraveSirRobbin
Moderator
The Ocelot doesn't use the conventional "coils" and "contacts" diagram structure of a typical PLC ladder logic program, but it's basis is very similar once you understand the command structure of the CMax program.
You will find the Ocelot's use of timers far superior than any other HA product out there!
You will find the Ocelot's use of timers far superior than any other HA product out there!
Slightly off topic
Anyone who is familiar with Ladder Logic and would like to dabble with Pic/Atmel micros might be interested in having a look here...
http://cq.cx/ladder.pl
Frank
Anyone who is familiar with Ladder Logic and would like to dabble with Pic/Atmel micros might be interested in having a look here...
http://cq.cx/ladder.pl
Frank
Lagerhead
Active Member
No, the Barionet is programmed in a conventional 2nd-3rd generation language -- a variant of BASIC.
Guys –
Thanks for the lead on the Ocelot. However, my reference to ladder is targeted at a system that adheres to the IEC61131-3 programming standard. Ladder logic is easy to learn and already has a rooted base of industrial programmers.
Rule logic and ladder logic are very similar. However, rules are generally event triggered. Ladder logic has the capability of state and event triggering. As an example,
Event Trigger = Whenever X Occurs, then trigger (and latch) Y
State Trigger = Whenever X State, then Y State (Y follows X)
In ladder, you can use a changing relay state to control an output (which essentially latches the output) or you can use a relay state to directly control the output. This limitation of event-only triggering can get a bit twisted in rule programming but maybe I’m used to the extra flexibility. I generally think in terms of states for PLC programming, otherwise I would use a sequencer.
Ladder is already GUI based programming. Today’s PLC programming tools have very powerful debugging tools and allow you to watch I/O real-time. Since the ladder looks like a wiring diagram, it is very intuitive to electrical techs.
A lot of complexity can be buried in PLC function blocks. Today’s PLC’s offer high level math, communication drivers, analog control including PID, high-speed inputs, etc, all buried inside of function blocks.
I guess that I’m looking for somewhat of a hybrid HA control solution given my industrial background.
Cheers and Happy New Year to All !
Thanks for the lead on the Ocelot. However, my reference to ladder is targeted at a system that adheres to the IEC61131-3 programming standard. Ladder logic is easy to learn and already has a rooted base of industrial programmers.
Rule logic and ladder logic are very similar. However, rules are generally event triggered. Ladder logic has the capability of state and event triggering. As an example,
Event Trigger = Whenever X Occurs, then trigger (and latch) Y
State Trigger = Whenever X State, then Y State (Y follows X)
In ladder, you can use a changing relay state to control an output (which essentially latches the output) or you can use a relay state to directly control the output. This limitation of event-only triggering can get a bit twisted in rule programming but maybe I’m used to the extra flexibility. I generally think in terms of states for PLC programming, otherwise I would use a sequencer.
Ladder is already GUI based programming. Today’s PLC programming tools have very powerful debugging tools and allow you to watch I/O real-time. Since the ladder looks like a wiring diagram, it is very intuitive to electrical techs.
A lot of complexity can be buried in PLC function blocks. Today’s PLC’s offer high level math, communication drivers, analog control including PID, high-speed inputs, etc, all buried inside of function blocks.
I guess that I’m looking for somewhat of a hybrid HA control solution given my industrial background.
Cheers and Happy New Year to All !
BraveSirRobbin
Moderator
I'm familiar with PLC programming, having done some in the past with Modicon Quantum PLC's via Concept (used more FBD and Sequential Flow than the 'true' Ladder Logic though).
I'm not saying there isn't a cheap/affordable alternative for home automation use, but I have not found it yet. The reason for the Ocelot suggestion is it comes in close, but again lacks the true visual programming and 'run state' that you seek.
I doubt you will get all the features you desire without actually obtaining a true industrial PLC. Maybe the Moxa line? If somone knows of an affordable alternative please let us know!
I'm not saying there isn't a cheap/affordable alternative for home automation use, but I have not found it yet. The reason for the Ocelot suggestion is it comes in close, but again lacks the true visual programming and 'run state' that you seek.
I doubt you will get all the features you desire without actually obtaining a true industrial PLC. Maybe the Moxa line? If somone knows of an affordable alternative please let us know!
123
Senior Member
fcwilt
Active Member
Just FYI, while there is nothing at all wrong with using ladder logic there is also nothing unique to ladder logic that allows this form of state/event handling. This can also be done using rule or procedure based logic. It's all a question of what features are provided by the software. One programmable controller that I like to use allows using ladder logic or procedure based logic or both. In fact, either approach compiles to the same code - that is to say I can write procedural code that exactly duplicates the function of the ladder logic diagram and vice-versa.
I find that each approach has its place and use either or both depending on the application.
I find that each approach has its place and use either or both depending on the application.
