adccommunitymod (AutomationDirect) asked a question.
Created Date: July 09,2014
Created By: smcmains
**** This post has been imported from our legacy forum. Information in this post may be outdated and links contained in the post may no longer work.****
I’m need to control 3 separate axis with a plc and hmi. I’m currently using 3 linear actuators from Oriental Motor as a 3 axis gantry system. These are great as the controllers are programmable with the laptop and set all aspects of the speed, accel, decal as well as position. I just give them an input as to what position number I want it to go to and it goes. The issue I’m having is when I need to tweek the points a little bit then I have to connect the laptop to each axis separately and program that point, which is a major pain. I would like to change my setup and use their controller as a driver and use the plc to do all the movement. In doing this I would like to use an HMI (c-more micro) and a plc (at this point I’m open to suggestions). I would like to be able to use the HMI to change the positions and speed of each point that the gantry will go to. It will make it so much easier if I can just pick the axis I want on the hmi and jog to the position I need, then manually change the value in the HMI. What PLC would be best for this application. I do not need synchronized axis movement, just very precise location, I would like position precision within .001” if possible. I have no experience with motion control but fairly proficient in PLC programming. We currently use DL05 & DL06 plc's alot in our plant but thinking a do-more PLC might be better? Sorry for the long post but I tried to include all info needed. Thanks, Steve
Created Date: July 09,2014
Created by: ControlsGuy
Assuming you 're planning on keeping the same servos, it seems to me that a key aspect in making your decision will be the ways in which that information can be dynamically sent to the servos. As far as what PLC to use, that's a pretty simple application (assuming you don't have to do anything heroic to get the settings into the servo), but Do-More is so much more user friendly id just use one and not worry about it.
Created Date: July 09,2014
Created by: Adisharr
Hi Steve,
Some of the Oriental drives can receive position info. serially. you might want to look at the capabilities of your particular drive. Many of them can talk Modbus RTU. You could use a Do-More and easily send new positions if needed. You could then use your existing control method of binary positioning if you like.
Anything serial for me these days sends me right to a Do-More. I don't use the DL06/06 anymore. There are many advantages to switching to the new platform. The software is free, well designed and mostly code compatible with the old systems. No more octal I/O, you can split your code up into sections easily manageable, etc..
Serially the platform is extremely powerful, one job I had involved a number of SMC position cylinders that I had to send different setpoints to based on a recipe and verify the positions were sent correctly. After the initial learning curve (most of that for the CRC checks), it's been working solid for a year now.
I'll stop blabbing now, I tend to get excited about working with the Do-More. :D
Created Date: July 09,2014
Created by: smcmains
Yes I would like to keep the motors the same, they are stepper motors for the linear actuator. Is it possible to change speeds and position points from the HMI using the H2-CTRIO2 module. All I need is a pulse for either CW/CCW and a feedback from the stepper motor (encoder) for actual position. Again, I'm new at linear motion so if these are stupid questions please excuse my ignorance.
Thanks,
Steve
Created Date: July 09,2014
Created by: scott.lawrence
actually, with the Do-More you can do all of that, and more :D
I have a three-axis system that uses the Do-More, separate H2-CTRIO-2 modules for each axis, and positioning is via the HMI.
Positioning down to .001 (inches) would depend on what the drives are capable of, Steps/Rev settings, and how noisy the system is.
Created Date: July 09,2014
Created by: smcmains
Thanks Scott, so you can actually modify the positions using the hmi? Are you using Dynamic Positioning for this and just store the position in a memory location via the hmi?
Created Date: July 09,2014
Created by: scott.lawrence
actually, there are 15 different screens with position entries for each axis, with 5-7 positions per part.
Each axis position entry has it's own register in the PLC, and I use a few MOVR instructions to place part data into 'run ' registers depending on which HMI page is opened...
here's a few screen shots for reference...
http://i.imgur.com/m6MwUY5.png
http://i.imgur.com/TJfdgjr.png
The system uses dynamic positioning, and at one time, there was talk of using encoder tapes, since the application is linear. But TBH, positioning for this system is in the .001/.002 range, so the tape wasn't needed after all.
Created Date: July 10,2014
Created by: BobO
If you plan to use a CTRIO2...use Do-more...no contest. Look into AXIS mode...
Created Date: July 10,2014
Created by: ControlsGuy
@Adisharr, why did you have to do CRC calcs? Or are you saying that some OM drives do Modbus RTU, but that your app used another protocol?
Update: OK, read your post again and think I got it this time. The Modbus comment was about Oriental Motor, whereas the CRC part was about SMC positioners (presumably using some proprietary SMC protocol, rather than Modbus).
Created Date: July 10,2014
Created by: smcmains
I'm not dead set on using the CTRIO2 and do-more but it looked like it might be the easiest way to be able to use the HMI to make position changes on the run.
Created Date: July 10,2014
Created by: scott.lawrence
I'm not dead set on using the CTRIO2 and do-more but it looked like it might be the easiest way to be able to use the HMI to make position changes on the run.
that would depend on the drives you 're controlling... I haven't looked them up or anything. Can you post a link to the exact drive?
This same project that I did with a Do-More was originally done with a DL260 & the H2-CTRIO modules. I only updated to the H2-CTRIO-2's b/c we were going to use encoders for position verification, and the 2's would accommodate that easier. I updated to the Do-More b/c of the H2-CTRIO-2's, and the limitations of email in the 260.
Also, if the drives have communication, you could do all of this without the CTRIO modules... just a thought.