Centroid Community CNC Support Forum

HMI Droid allows us to see and control the Click PLC from a iPhone, Android Phone or Android Tablet. I picked up an inexpensive Lenovo tablet to test things out. It took a little searching through the HMI Droid Studio Manual to find how Click variables are mapped, but once that section was found, everything came together. Here's a screen shot of some test data that I used to verify that different Click inputs/outputs/coils were working. The data is for my test purposes only, i.e., to show that the on-screen LEDs change state when a proximity sensor detects a limit or when I cause aClearPath motor to fault. The Android tablet uses WiFi to connect to the Click PLC. After telling HMI Droid which protocol, which IP address, which Port and how frequently to poll the Click PLC, everything came together. If you decide to try doing this, send me a private message, since this subject is only indirectly related to using an Acorn.

Richards,
AWESOME job man, very nice.

Russ

The Android Tablet is working well as a HMI device for the Click PLC. Here are two screen shots.

This screen shows the status of some of the PLC's Input/Outputs This screen shows the manual setup/manipulation of the power supplies

It's been a while since I reported on how the AutomationDirect PLCs are working with the Acorn board. I started out with the CLICK C0-10DRE-D (Ethernet, RS232, Relay outputs, about $175 with PS). Next I tried a C0-11DRE-D (same as the other but with an RS485 modbus port, about $200 with PS). Then I tried the Productivity 1000 PLC. That PLC is almost beyond belief. It ran circles around the CLICKS and only cost about $60 more. Just today I received the bare bones entry level C0-00DD1-D, about $100 with PS). It works perfectly.

The least expensive PLC is more than adequate for what I'm doing. Granted, when more I/O that is added, more modules are needed.

Unless you think that all of these PLCs are overkill, I also work as a consultant to the oil pipeline industry where they use GE PLCs that easily cost $15,000 just for the PLC, PS, cage and a few modules. Just last week, I was able to listen in while they added two $750,000 VFDs and motors to run two pumps. These cheap AutomationDirect PLCs let me test logic quickly and affordably. Because the pipeline people use a lot of ModBus communications, I can easily duplicate their communications, both RS485 and Ethernet.

When I read about the frustration that some users are having (mostly because it appears that building an Acorn based CNC controller might be their first attempt at serious electronics) I just wish that we had a way to more easily share information without the need of extensive study and/or trial and error. My solution is to add a PLC. Gary and Keith have had excellent results with using relays to steer signals. Marty and others have worked through the issues and then showed us how they did it on YouTube.Their expertise and willingness to share makes these projects possible for the rest of us. Bottom line: There doesn't seem to be a universal solution for everything, but I've found enough information on the forum and on YouTube to do everything that needs doing.

Richards wrote: ↑Mon Mar 25, 2019 11:56 pm It's been a while since I reported on how the AutomationDirect PLCs are working with the Acorn board. I started out with the CLICK C0-10DRE-D (Ethernet, RS232, Relay outputs, about $175 with PS). Next I tried a C0-11DRE-D (same as the other but with an RS485 modbus port, about $200 with PS). Then I tried the Productivity 1000 PLC. That PLC is almost beyond belief. It ran circles around the CLICKS and only cost about $60 more. Just today I received the bare bones entry level C0-00DD1-D, about $100 with PS). It works perfectly.

The least expensive PLC is more than adequate for what I'm doing. Granted, when more I/O that is added, more modules are needed.

Unless you think that all of these PLCs are overkill, I also work as a consultant to the oil pipeline industry where they use GE PLCs that easily cost $15,000 just for the PLC, PS, cage and a few modules. Just last week, I was able to listen in while they added two $750,000 VFDs and motors to run two pumps. These cheap AutomationDirect PLCs let me test logic quickly and affordably. Because the pipeline people use a lot of ModBus communications, I can easily duplicate their communications, both RS485 and Ethernet.

When I read about the frustration that some users are having (mostly because it appears that building an Acorn based CNC controller might be their first attempt at serious electronics) I just wish that we had a way to more easily share information without the need of extensive study and/or trial and error. My solution is to add a PLC. Gary and Keith have had excellent results with using relays to steer signals. Marty and others have worked through the issues and then showed us how they did it on YouTube.Their expertise and willingness to share makes these projects possible for the rest of us. Bottom line: There doesn't seem to be a universal solution for everything, but I've found enough information on the forum and on YouTube to do everything that needs doing.

Thanks for the post Mike. Understanding motion control systems and PLCs helps certain people think outside the box.
Thanks

Marty

Richards wrote: ↑Mon Mar 25, 2019 11:56 pm It's been a while since I reported on how the AutomationDirect PLCs are working with the Acorn board. I started out with the CLICK C0-10DRE-D (Ethernet, RS232, Relay outputs, about $175 with PS). Next I tried a C0-11DRE-D (same as the other but with an RS485 modbus port, about $200 with PS). Then I tried the Productivity 1000 PLC. That PLC is almost beyond belief. It ran circles around the CLICKS and only cost about $60 more. Just today I received the bare bones entry level C0-00DD1-D, about $100 with PS). It works perfectly.

The least expensive PLC is more than adequate for what I'm doing. Granted, when more I/O that is added, more modules are needed.

Unless you think that all of these PLCs are overkill, I also work as a consultant to the oil pipeline industry where they use GE PLCs that easily cost $15,000 just for the PLC, PS, cage and a few modules. Just last week, I was able to listen in while they added two $750,000 VFDs and motors to run two pumps. These cheap AutomationDirect PLCs let me test logic quickly and affordably. Because the pipeline people use a lot of ModBus communications, I can easily duplicate their communications, both RS485 and Ethernet.

When I read about the frustration that some users are having (mostly because it appears that building an Acorn based CNC controller might be their first attempt at serious electronics) I just wish that we had a way to more easily share information without the need of extensive study and/or trial and error. My solution is to add a PLC. Gary and Keith have had excellent results with using relays to steer signals. Marty and others have worked through the issues and then showed us how they did it on YouTube.Their expertise and willingness to share makes these projects possible for the rest of us. Bottom line: There doesn't seem to be a universal solution for everything, but I've found enough information on the forum and on YouTube to do everything that needs doing.

I am now a firm believer in this philosophy. In my case, I built my first 'draft' system from the Clearpath 3 design schematic. Problems existed and I rewired to the CP 4 scheme. This is only after I did a lot of re-inspection of my own work, believing that the design plans were already proven and robust.

Some of my problems stemmed from wiring the CP HL outputs for the servo fault protection. While I got the 8x relay board to take the signals, a drop out of one of the HL outputs on the CP would not fault the whole system. Clearly, problems still existed. I got tired of wiring and rewiring... trying to fix what I considered to be a clunky, ad-hoc solution.

Talking to Mike reminded me of a lesson long known. PLCs save wire, time and parts cost.

Frankly, I was really wanting AC to work without my introduction of 3rd party parts. In my mind, the addition of additional parts would make the system less robust. However, when you consider what a PLC does, it replaces physical parts and physical connections. In 7 minutes I wrote the code to handle my HL Clearpath circuits. I wired it, it is fast, it works flawlessly. I saved 3 relays on my system and the introduction of a second relay board. The relay board takes space, wire comes with extra points of failure... as does series wiring a daisy chain of 3 relays.

A PLC is made for this.

I am not an Acorn pro... I am a neophyte with it, so you don't want to ask me about helping out with any other systems. I still am looking for input on my own. However the trepidation of 'not modifying it' by adding a PLC was a mistake.

I cannot say that everyone should add a PLC! However if you have some knowledge of them, and see a spot where they will fit in and make your job easier, by all means put it in!

Let Acorn do its thing. Offloading some of the logic to a platform you feel comfortable with is a great idea.

Personally, I think Mike's topic here deserves a sub-forum.
*** No wires were harmed in the making of this circuit!

This represents the series connections of the CP HL circuits to the fault input. And while I don't have my home set up yet, I could not help but take 3 minutes and wire it in the PLC as well.

A lot of options open up when you have a little experience with a PLC.

I have to thank Mike again for sharing his ideas on this topic, and with me.

Cheers!

Since first posting, I've received several emails from users who are thinking about using a PLC in addition to the Acorn. PLEASE keep in mind that a PLC has a scan or loop time that may need to be accounted for. Most PLC literature states that a PLC first scans all of the Inputs, then works through the rungs (logic) and finally sends signals to the Outputs. Any particular PLC may do things that way or some other way. The important thing to know is that if a signal needs to be read and acted upon in less than 1 or 2 milliseconds, a PLC may be too slow.

A PLC should NEVER be inserted between the Acorn's Step and Direction signals and the motor driver. On the other hand, sensing motor faults, sensing home position, sequencing power supplies and monitoring/controlling locating pins, vacuum on/off, etc. will probably work just fine with a PLC.

I have tested several versions of AutomationDirect.com's CLICK PLC and their Productivity 1000 PLC. The $69 CLICKs seem to have a 2 millisecond scan time for very simple setups. The ethernet models can handle much larger programs at 1-2 milliseconds. The Productivity 1000 is mostly faster, but because it has some heavy-duty capabilities, the scan time is highly dependent on what you use that PLC to do. The CLICK PLCs have an interrupt command that handles time sensitive I/O, but use caution if you use the interrupt command or response time will suffer.

For homing routines where the PLC handles several proximity sensors and does the logic conversion, the axes should be moving slowly, so accuracy is good. However, if you're in high-speed jog mode when a limit sensor is tripped, 2 milliseconds allows an axis to move 0.02 inches at 10 ips or 0.04 inches at 20 ips. That might require you to rehome the machine.

It's also a very good idea to know the response time of your inputs and your outputs. Inputs and Outputs take time to act/react. Depending on the quality of a proximity sensor and its distance from the target (1mm, 2mm, 3mm or greater), its response time may be affected. I have some relays that take 20msecs to turn on. So, be aware that there are gremlins out there that can mess with your design. Read the literature carefully. Do the math. If you've done that and things still look good, then give a PLC a try.

Just a reminder that Acorn Expansion module is on the not too distant horizon.
That said, PLC's especially those easy to program are handy devices.

Marty

Thanks Marty.

I'm anxious to see how the Acorn expansion board connects to the Acorn. I know that it will have an ethernet interface, but will the expansion board itself be expandable? It would be just my luck that I'd need 17 extra inputs (which isn't so far fetched because I use 24 extra inputs on one of my PLCs to test an "ultimate router" concept). That semi-fictional router only needs to be tightly connected to the Acorn for axis movement and for spindle speed control. The homing/limit switches, vacuum zones controls, sheet material pop-up pins, and tool changer only need simple signals from the Acorn to start their specialized routines at which point the PLC takes over, does its task and then gives the OK to the Acorn to continue. That type of ModBus communication has been part of the automation world since the early 80s. That's also the main reason that I have five PLCs - to test RS485 ModBus and Ethernet communication where tasks are distributed. So far its working well. The PLCs talk to each other and to an Android Tablet HMI device over ethernet and WiFi. They also talk to some inexpensive Arduino Micro Pros ($5 each) with RS-485 boards ($2) for temperature sensing on an auxiliary project.

I realize that what I'm writing about is far beyond the envisioned use of an Acorn, especially when Centroid has already addressed that kind of expansion with its All-In-One and Oak boards, but, on the other hand, when ModBus is available on the Arduino, the Raspberry Pi and on all versions of the BeagleBoard and given the fact that the Acorn already has tons of PLC code incorporated in it, I'm wondering if its true potential will be released?

Spot on Mike. I was directed to your post by a search for how to get my saved draft posted for my new build. Asking for help simply wiring two default preprogrammed buttons to one preprogramed output.
During the "simple" configuration of the VCP and CNC12 to my simple machine has been frustrating. My Industrial Engineering background is champing at the bit to provide suggested improvements to this process. My weed hopper Code Monkey certification led me to Visual Programming Languages as a easy upgrade. Between your 2019 post and today I have not seen a lot of added documentation addressing the critical nature of timing issues you pointed out that include guillotine e-stop shut downs on VFD braking resistor requirements et al.


To forum moderators were is the best place to post suggestions for general support documentation?