E-Stop Not Working with 424/MACH4 with NO-(mom) Closed Switch

[ScottC]

I just received my new 424 board and i can not get E-Stop to work with my NO (mom) closed switch.  I used your 411 unit on another project with same switch before and it worked perfectly.
My Connection> Switch: NO (mom) closed ... the E-Stop pin is showing it is pulled up to ~4.37V

I have monitored the PMDX SmartBOB Diagnostics application and it shows the pin changing state from active high to active low.  Yet when i monitor at the same time the MACH4 diagnostics screen the E-Stop button always shows red no matter if i have it active low or high in MACH4 setup.

What i am i missing here ... must i use a NC (mom) Open switch for my E-Stop?

Scott

[Bob at PMDX]

One difference between the PMDX-411 and PMDX-424 is that the PMDX-424 has a dedicated EStop input and the plug-in presents this as an input signal called "EStop".  With the PMDX-411, you probably used "Pin10" or one of the other input pins.  Since the plug-in's real-time display shows the EStop input togging on and off (I presume you were looking at the EStop indicator) , my first guess is that you have the Mach4 "E-Stop" signal mapped to a different input.

Go to the "Configure" menu and select "Mach..".  Then click on the "Input Signals" tab.  Scroll down to the "E-Stop" signal and make sure it is mapped to the SmartBOBUSB "EStop" input, with a red "X" in the "Active Low" column.

Bob

[ScottC]

Bob,

Thank you for quick reply!

I have the setup exactly as you suggested and it does work only if i keep the button pushed with my finger all the time.  I also noticed the system will not boot up properly unless the switch is pulled low at start up.

Note i am trying to use a switch that is normally open and momentary closed for my E-Stop.  Is it not possible to use this type of switch with 424 and MACH4?

Scott

[Bob at PMDX]

I was typing the answer below as you entered your second question.  So, the answer is "yes, but..."

My Connection> Switch: NO (mom) closed ... the E-Stop pin is showing it is pulled up to ~4.37V

Oops - I forgot to address this issue.  For a normally open EStop switch, you should keep the jumper that we provide on J14 between the EStop input and GND.  You then should wire your normally-open switch to J14 between the /FAULT and GND terminals.

I would, however, HIGHLY recommend not using a momentary contact switch for the EStop signal.  The idea of an EStop is to keep the machine disable until whatever the problem was has been fixed or cleared.  By having the EStop switch latch, you have a mechanical backup to the hope that nobody comes by and hits the "Enable" button in Mach while you have your hands in the machine.

Also, there is a concern in making sure the EStop signal is asserted long enough to be guaranteed of being reported to Mach4.  With the PMDX-424 this is less of a concern in that the PMDX-424 will latch any active EStop transition until it has been reported to Mach4.  However, there may be situations where that ONE communication packet is lost or corrupted and Mach4 doesn't actually see the EStop.  And with the PMDX-411 there is no latching function in the device.  So if there is a short pulse on the EStop input (as *could* be the case with a momentary contact switch being pressed in a hurry), there is absolutely NO guarantee of that event being passed on to Mach4.

Bob

[ScottC]

Bob ... Noted i will change the switch!

I do have a question until my new switch comes in, i would like to get my machine running to get my code up also.  I notice the fault switch input is not listed as one of the selections in the setup are the fault and E-stop connected together in some way?

Side Note: How to i activate the 5V to the common pins for my driver?  I don't seem to see this in my notes that was sent with my 424 ... if you direct me to were to look i will do so.

Thank again for your support of your product!!!

Scott

[Bob at PMDX]

I notice the fault switch input is not listed as one of the selections in the setup are the fault and E-stop connected together in some way?

Yes, they both control the "EStop" input signal from the device to Mach4.

Side Note: How to i activate the 5V to the common pins for my driver?  I don't seem to see this in my notes that was sent with my 424 ... if you direct me to were to look i will do so.

Go to our plug-in configuration and click on the "Motor Config" tab.  Near the top right of the window you will see a section labeled "Step/Dir Common".  Note that this section is only visible when you are connected to a PMDX-424.  I give this a brief mention in the table in section 2.9.4 of the quick start guide, but it could be a bit clearer and easier to find.

Bob

[ScottC]

Thanks Bob,

I tested it while i was waiting for your reply.  It works great!

As for 5 volts to common pins for driver ... I put another request for this by itself on forum ... please disregard or copy response there maybe other will see it.

Thank again

Scott