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Messages - simpson36

651
Trying to find a way to notify user if modbus connection dies for any reason.

Docs on MACH's modbus implementation are sparse and I don't find any way to query MACH for Modbus status.

The application is to be able to E-stop MACH from an external source if the Modbus com stops for any reason.

If it is not possible to query MACH, then what methods are people using to monitor the connection?

A character could be sent and retrieved by the slave and a hardwired signal used to notify the user of a problem, but it seems there should be a way to query MACH.

652
Finally, the last piece of the puzzle; a comprehensive motor controller specifically designed to take advantage of the 4ths axis Indexing and Turning capabilities.

Check out the YouTube video - link here: http://www.youtube.com/watch?v=vBLuF_F2_qs

This new motor control took 200 hours to develop and is a complete system consisting of the control box seen in the photo below, 15 or so 'control' macros, another 20 or so embedded macros ('M' macros to embed in G-Code) a Mach brain program, and a set of custom Mach screens.

The controller has its own PLC and generates its own step and direction signals independent of Mach, but it is also tied into Mach to retrieve and deliver data for two separate speed modes and also retains all normal indexing 'A' axis functionality.

My favorite feature (other than being able to control the 4th axis with screen clicks instead of manually entering macros into the MDI) is what I call 'AutoSpeed'. This mode monitors the distance from center of the cutting tool on either the Z or Y axis and automatically calculates the 4th axis spindle RPM to maintain a specified SFM. A significant portion of the 200 hours of development time went into creating this mode.

Over 2,000 lines of C code run on the internal PLC and the controller is connected to Mach thru ModBus. The PLC can also communicate using Modbus Ethernet, but that version of ModBus lacks some features that I need for certain operations, so I had to stay with the slower interface.







653
SmoothStepper USB / Re: Ethernet SmoothStepper first test
« on: January 24, 2012, 04:30:32 AM »
Works for me. My A is linear,
I should have been more specific. Rotary axis are more troublesome because the duration of the signal is very short.

The issue is resolved, in any case. The problem was noise on the signal line. I am using (for the moment) a special smoothstepper BOB made by CNC4PC. The BOB has filters on the inputs which might have contributed. Trying to run crap thru a crap filter is not a good process. I have had this smoothstepper in a box for about a year, and with the release of the new plug-in, I decided to give it another try. So while I have had it for quite a while, I am still a noobie and learning the quirks. The BOB, incidentally, has port 2 locked as inputs, which is probably OK for most setups, but  I need outputs and so had to modify the board.

FWIW, the solution consisted of several changes. First, the inputs were pulled high. I don't know at this point if that is from the smoothstepper or the BOB but I had to put a 1K pulldown on the pin to shut it off, then drive thru it with the remainder of a 5V signal running thru a rather hungry opto. I have about 3.7V at the pin for the 'ON' signal and .68 for OFF. Not ideal, but it is working. In addition, I had to set the smoothstepper filter to a value of 1.0 and drop back to the previous plug-in (prior to the eb).

I am not satisfied completely with this solution and I would categorize it as a workaround. However, the 4th axis is homing now and I can get on with my project. I'm not giving up on the smoothstepper just yet, however, the BOB will be going away and having discovered how sensitive the smoothstepper is, I'll be providing separate super clean 5V power to it and pay close attention to the grounding.

New Q about the ESS: does the new board have the same annoying ultra persistent, un dismissable error splash screens as the USB version? That in itself would be reason enough to avoid it, in my view. 

 

654
SmoothStepper USB / Re: Ethernet SmoothStepper first test
« on: January 23, 2012, 02:54:55 PM »
Does A axis homing work with the ESS?

I cannot get it to work at all with the USB version . . the A axis Home sensor light up on the Mach diag screen and the checkbox in SS data window toggles, but Mach just ignores the hit.

I have even manually hit the pin with 5V just in case the sensor signal was weak or of too short duration. Nada.  Have tries several different pins on SS. Nada.

Works fine on PP.

Is this a known problem?

655
Show"N"Tell ( Your Machines) / Re: Conect 121 lathe retro
« on: January 20, 2012, 05:40:00 PM »
Thanks for the info.

You mention 24V inputs and from that I am assuming that you do not have isolation on the I/O.

What I did was isolate everything so it does not matter if the signals are 5V, 12V, 24V or actually any voltage up to the opto's rating. I this way, you do not have to have different components or different boards and the drives are 100% protected.

656
A UPS probably will not help. A line filter will. And moving the PC and the motor power supply to different power circuits can have a positive effect.

Random 'spookie' issues in general can be caused by voltages that are hovering near the ON/Off TTL threshhold. Make sure you do not have a newer 3.3V parallel port driving a 5V BOB.

Assuming all of that is OK, add pull-up or pull-down resistors the the pins that are causing trouble. i.e. hold then up or down away from the threshold.

Practical example: Say your E-stop line goes HIGH to activate E-Stop. Put a 10K resistor between that pin and ground. This will hold the signal OFF and keep it from wandering all over the place from induced voltage. When your E_stop goes HIGH, it will have no trouble driving thru the 10K resistor to pull the pin HIGH. Still, check it to be sure.

Conversely, if your E-stop goes LOW, then put the same resistor frm the pin to 5V to hold the pin HIGH until the E-stop signal pulls it down. Some BOBs have these pull-up/pull-down resistors built in. If your BOB has these, make sure that they are set to pull in the right direction as described above.

657
Show"N"Tell ( Your Machines) / Re: Conect 121 lathe retro
« on: January 20, 2012, 04:49:03 PM »
Hood,

Thanks for the PM heads up on this project. I have a few Q's

I understand the differential outputs, but what is the purpose of differential inputs?  Are these foe encoder feedback or something similar?

Can you make these boards capable of being plugged directly onto a smoothstepper?
Incidentally, I know you have the ESS, so I'll sneak in a Q; is the ESS dimentionally similar to the original? i.e. a BOB made to fit the Original will fit the ESS?

How many axis will you have on a single board? Shall I just count the diff outputs and make an assumption?

Edit: I suppose it would be good to ask if you have alreay produced the boards and/or is tweaking a possibility. I am thinking about combining several of my boards into a smoothstepper compatible BOB and there is no sense in re-inventing the wheel. Typically I don't use OP work, but I have seen some boards that you have built in the past and they are high quality.

658
SmoothStepper USB / Re: Ethernet SmoothStepper first test
« on: January 19, 2012, 09:17:53 AM »
It works fine with Modbus TCP/IP devices. I've tested it with my ModIP prototypes.
Thanks, Peter.

Couple Q's;
Are you going to be selling the 'ESS'?
Any plans to make a custom BOB for it? As long as I'm asking, how about one with differential signal outputs?
Any plans to offer a general purpose PLC pre-configured with TCP modbus?

I am just finishing up my long overdue 4th axis motor controller. It is 2,000 lines of C code running on an Arduino Mega board. I have it working with vanilla serial Modbus and also with TCP modbus. TCP modbus would be preferable, theoreticaly, but I read here and elsewhere that TCPmodbus in MACH is unstable. Can you offer an opinion on that?

659
SmoothStepper USB / Re: Ethernet SmoothStepper first test
« on: January 19, 2012, 05:39:21 AM »
I jumped on here to ask about ESS swapaxis, so I have that answer, thanks!

Does anyone know if the ESS can co-exist with TCP modbus?   (I will take time later to read this entire thread, but for now I would much appreciate an answer to this if anyone knows).

660
General Mach Discussion / Re: High Speed Servo as Spindle - My Solution
« on: January 18, 2012, 03:54:32 AM »
Last post to this thread. Project completed and software is in beta and ready for customer testing. If I have time I will add a video to my YouTube account that follows this project. Here is the final control box and screen mods: