Tablet control, am I missing something?

[244]

There are a lot of reasons running anything industrial on a pad is a bad idea. Not trying to knock any ones product but this is not a good idea.

Care to elaborate? It's been my understanding that PLC's were the control of choice due to harsh industrial environments; vibrations, bad air,
heat/cold, etc, that an actual computer couldn't handle. With the advent of SSDs and no-moving-parts computers I would think that the majority
of those concerns have been invalidated. This is speaking strictly from an hardware angle of course.

Software wise, while a virus infecting your press would be ridiculous, unless specifically designed to do so the likelihood of any
random virus causing damage or a misbehaving press is pretty much nil.

And it's software to control a press, not a desktop computer. You won't have employees surfing to sketchyass websites opening
questionable email attachments, which is the major vector for infection. Granted if it is networked (and who could resist that) you have
the possibility of something spreading to it that way.

New ideas are always great, and anybody that has been stuck with a dead PLC can appreciate reinstalling software locally.
Time will tell I suppose.

PC-based systems running a Windows operating system (OS) are not a good solution for real-time operations because a PC is not deterministic, i.e., you cannot guarantee a response time to interrupts and tasks. A PLC, on the other hand, has a guaranteed scan time, ensuring its I/O and interrupts are serviced on a regular basis. What that means in layman terms is you send out a signal to do a function and the PLC will go no further if within the allotted time frame it does not get a signal back to confirm function. A PC will send out a signal and even without confirmation will continue on or send multiple signals. Imagine a car doing 60 and you need to slow down. You take  your foot off the gas but the car doesn't need to confirm it so it keeps going down the road at 60. If the car had to confirm the gas was off as in a fail safe situation the car would slow down. This and the fact that a tablet is not designed for machine vibrations, heated environments, and does not have the safety of being deterministic are the reason for my statement. also while minor the operating system used for programming is not a stable platform. Microsoft changes this often and that will affect the long term support for your pad.

[TCT]

Cool thanks for your input Rich. I really appreciate you dumbing it down for us screen printers   I fully admit we are over my head on this technical stuff.

Is the vibration really a concern? All the machines I can think of currently with a tablet control are all servo index, and I can only think of one(the forthcoming MHM SA-EVO) that has pneumatic heads. I would think vibrations would minimal at best. I understand that is only one issue out of a few that were listed.

Good discussion though guys! I am super happy I brought it up because I love the technological advancement aspect of the tablet idea but I was just not completely understanding the benefits/drawbacks.

[ebscreen]

I'd think that if a tablet can handle the abuses of daily travel it shouldn't have an issue with being attached to a machine.

I'm no Windows fan by any means, but apparently they developed a Robotics Development Kit back in 2007 to handle
the deterministic issue.

I think that our machines fall under a slightly different category than a huge milling machine or a laser for automotive manufacturing.

In terms of future support, I'm going to have to side with a PC. Even if the software changes, that's adaptable. Finding the ladder logic
program for a NLA Mitsubishi PLC? Let alone IO modules? NLA means what it means.

Alex, do you happen to know what PLC your S-Roque uses? My MHM's use Hitachi's, and while I have never had an issue with them, even when
the battery goes dead and needs to be replaced, parts availability is almost nil.

[TCT]

I want to say it is APC or something like that.... I can't for the life of me remember right now. I can look when I get in tomorrow though!

[Sbrem]

I think that it's less expensive to fix the control panel. Say $500 to get a new tablet, download the program, back up and running within say an hour. That's what I got (understood) from workhorse. I'm sure there are other advantages.

Sent from my DROID RAZR HD using Tapatalk

When we broke our MHM panel a few years ago, it was 3 -4k, so a new tablet is certainly less than that.

Steve

[TCT]

Alex, do you happen to know what PLC your S-Roque uses? My MHM's use Hitachi's, and while I have never had an issue with them, even when
the battery goes dead and needs to be replaced, parts availability is almost nil.

Hey man sorry about that, turns out "tomorrow" turned into a week! I was installing a new program on the press today and while the brand was staring me in the face it rang a bell!!!
The panel the S-Roques use is a Beijer. I am pretty sure after the first of the year all their presses use them now. Anyway there is a office in Utah. Here is a link to my exact panel-
http://www.beijerelectronics.com/web/web_en_be_com.nsf/alldocuments/6666452DE5742394C125786A0027EE37