Jogging motors from a mobile device (safety considerations)

[omora]

I am pondering the use of some tablets running Ignition as mobile HMIs along a conveyor line. The problem is, I haven’t found a tablet/laptop with wireless E-Stop capabilities. Is it okay to allow the operators to use the HMI to run/jog pieces of equipment without an E-Stop nearby?
I don’t want to use an umbilical cable.

[pturmel]

HMIs are notorious for stuck bits. Mostly due to the unreliable nature of TCP/IP. Made worse with SCADA packages because the comms make two TCP/IP hops, not just one. (HMI => Gateway => PLC.)

I wouldn't do it.

See this (rather contentious post) for more background:

Very Concerning Read/Write Issues. Important information for all users

Hello Ignition Members, Disclaimer - All of our senior designers/programmers are qualified for their jobs where I work. These problems are described as I see them, they may not be exactly what happened. Therefor they are to be used for troubleshooting the issue only. Thank you. We are in contact with some ignition developers and are desperately trying to fix this problem. This is a GLOBAL problem therefore it won’t be affecting just us. It may be affecting anyone who is using ignition well. Ti…

Also search this forum for "momentary".

Note that much of the material and available work-arounds are focused on the Vision module. I don't know of any work-around or reliable momentary button functionality for Perspective (yet?).

[pturmel]

Also, note that there are purpose-built solutions from the major brands that include estop and/or grip-safeties, like this family of products from Siemens:

SIMATIC HMI Mobile Panels

[omora]

Thanks for your comments. I am from the same opinion but wanted to explore other people’s opinion and I am glad to find I am not alone on this. ‘safety first’.