Grettings,

    I have been talking on and off with Greg about a SS Drop out issue, Greg suspects it may be a ground issue, BUT, The Issue dissappears when a Modbus Driven PLC is taken out of the equation.  (althought it shares panel ground with the SS external power supply).

    I was wondering, If anyone here is running a SS, + Modbus/PLC + Brains + a simple Macro pump can you see if your SS will just disappear from the Mach3?
My Set up: Through Serial Modbus I am talking to a standard DL06, the ladder in the PLC is not complex, it is just straight trough I/O plus an Analog Output for Spindle control, and an analog input that reports back true spindle speed from the Spindle Drive.  The PLC has control over the digital inputs/outputs of the AC drives i.e. Servo enable, fault reset, spindle fault.
and it does basic I/O control of the spindle and the I/O of the ATC on the spindle.  Mach going through basic Brains that transfer the information from and to the PLC from the screen set in mach.  I only use the Macro pump to send Error messages, about faults.

I was hoping someone who is running a SS, plus a PLC and Brians can they see if they think there may be somekind of Software conflict inside mach3 that may be causing a Bug with the SS Plug in.  The PLC and Brains are NOT complex just striaght through I/O, and not neccessarily alot of I/O eigther.

I, like Greg think it may be a ground loop issue, but I am trying to elimate other potential issues, so if someone here can look at their set up to see if they run into a Drop problem with the SS.

Thanks,

Scott

I have a PLC and a couple of very simple Brains on the lathe with a SS and no problems. The Brains dont interact with the PLC so that may be different from yours? Also no analogue on the PLC on this machine so again that could be different.

Hood

Hey Hood, thank you sir for your help,

  I am running several Brains each one a differnt thing, like one for discrete inputs, one for outputs, one for analog in, one for analog out, one for problem conditions
The brains are just straight through I/O, the PLC is just In/Out ladder that sends I/O to/from Mach serial modbus. I run a macro pump but it only does stuff like display a "Ticker Message" for Errors or problems since Brians wont do Strings.  I have built several machines like this, but this is the 1st time and issue like the SS dropping out has reared its head.

So bottom line is with your set up, since you not having suspected software conflicts, How is your SS powered?  How is it grounded, what is your Electrical set up for the SS, computer, and Cabnet.

scott

SS is powered from the computers power supply and is not grounded other than through the usb cable. Computer is a pico mobo and is in the electrical cabinet and fixed to the panel so it will be grounded. All other ground wires go to one fixed point in the cabinet. Think I may have some pics of the cabinet but it will be previous to me having the pico but can post if you wish?

Hood

Hood,

     More, and more, I am beginning to believe it is an Grounding fault issue.

But, IF you can play a little, can you add some "Phantom I/O" to your PLC and add some to your Brains mabey.

The set up I have moves about 24 In (20 discrete Plus 4 analog), and 18 out (16 discrete, plus 2 out).
Mabey run a Macropump as well that has some kind of bogus code in it, I just want to see if a combination of Modbus, Brians and Macro pump may conflict with the SS Plug in...   If yours does not, then I will consider the software issue as a Non-potential problem area.

scott

ok Scott, set up a Brain to look at one of my panels buttons (operates through the PLC) and press the start button, made a macropump to look for the start LED and give me a message, all worked and SS is fine.
Hood

Hood,

   Thank you sir for your time and help in this matter.  Given your findings as well as my own past experience, I will say that it is a grounding issue.

   the Client that I did was Precix Mexico (see the pics of the two routers in the machine section), I did mention to them that you have grounded ALL of your device grounds to a central location, including: Computer, Panel, and SS.

  I am having them retrace all of thier wiring to see if something else be tied to ground that is not suppossed to be, and move to a "Star" ground. 

We did try one of those "USB Opto Isolator" cables but that did not resolve it eighther. We had tried using the SS powered from the computer, and then tried an external power supply for the SS. None of these seamed to make a difference in the random dissapearance of the SS from off the system.  Greg, my self and the client has all "Skyped" a touble shooting session, and I think slowly coming to a concensous that the loop issue is a culprit. Now, the hard part is finding it...........

Again, thank you so very, very much for your time and help!!!

Regards,

Scott

Remember that DC common is not the same thing as ground. The 'earth' ground should not be used to carry any current, i.e. it should not be used as a return path for any sensor, switch, lamp etc. Doing so makes the ground plane sort of an antenna...

Jeff, we (I) are talking about Earth ground issues in the above convo. The problem is they are somehow getting noise back through the ground plane, probably through the VFD even though it is 6' away an on a different power cuircuit.

thanks though for your input,

scott

Yeah, Scott, what I'm trying to say is that if you have DC commons bounded to your Earth ground all over the place you'll have similar problems. Things like having shield braids earth grounded at both ends will do it too.