[GORDYKD]

I am assisting the setup of a lathe that uses a VFD for spindle drive controlled by a KANALOG. During boot there is an output from the JP13 CH 0 that causes the spindle to run. This lasts about 3 seconds. Is this a failure of the board or is there a configuration missing that should disable the channels while booting?

[TomKerekes]

Unfortunately the Kanalog Outputs Power up in an initially undetermined state for several seconds until KFLOP boots up. If this is a problem for your system then another means of keeping the Drives disabled should be used during initial power up. The Kanalog SWE Relay Output Driver is guaranteed to remain disabled until KFLOP fully boots and all Kanalog Outputs are initialized to the off state.

Regards

[john-100]

with outputs starting at random states
one solution could be to use a timer circuit to disable the Kanalog signals at switch on
until the Kanalog outputs are valid

John

[GORDYKD]

Thanks Tom, I wondered if that was the case. Is there a system ready signal that can be used or do I just have an output set to high to drive a relay?

[Al_The_Man]

A proper industry-standard hard wired E-stop circuit would cure all this, power to motor systems should not be on until the system is ready.
Post #14 http://www.cnczone.com/forums/bencht...egulators.html
Al.

[GORDYKD]

TOTALLY AGREE Al, I have had several conversations with the designer/builder about this. Unfortunately he doesn't seem to fully understand the importance of TOTAL control of everything when an E-STOP is hit. Still working to try to remedy the fact that if the drive is in a programmed move the endpoint is in memory so even though the E-STOP near the operator, wired as an input to the Kanalog board, is pushed the drive will continue to it's destination. I couldn't believe it when I saw it. The other E-STOP on the main panel is supposed to kill all power, but was not wired that way to start with. It was wired also as an input to the Kanalog board I will be changing so both will kill EVERYTHING. I truly believe stop means STOP.

A proper industry-standard hard wired E-stop circuit would cure all this, power to motor systems should not be on until the system is ready.
Post #14 http://www.cnczone.com/forums/bencht...egulators.html
Al.

[Al_The_Man]

Considering just how often this issue comes up, I'm surprised that offerer's of small CNC style controllers do not include a suggested simple circuit that will do just this, the simple tried and true control relay has been a standard method applied since the inception of industrial motion control.
Al.

[GORDYKD]

Al,
Unfortunately with the abundance of inexpensive control systems and components, anyone with a rudimentary understanding of programming and some basic electrical and mechanical knowledge can build and market a machine. Even though almost no thought has gone into the safety of said machine. One of the few instances where I would advocate some type of certification requirement on the part of the builder.

Kent

[Al_The_Man]

Al,
Even though almost no thought has gone into the safety of said machine.

Not to mention the safety of the user. .
Al.

[TomKerekes]

Hi GORDYKD,

Is there a system ready signal that can be used or do I just have an output set to high to drive a relay?

Again the Kanalog SWE relay driver output is guaranteed to be off and remain off until after KFLOP Boots and all the Kanalog Outputs are initialized to the default off state. It then goes active.

[Greg9504]

I hesitate to post this, but this is what I do for my enable on power up of my axis (which are actually ac induction motors controlled by VFD). I do have an estop but it is already wired to the VFD's directly, as I get things sorted out I'll look into Al_the_Man's Shunt Regulators. Anyway using a couple of opto couplers with the SWE signal it's easy to have control over the KAnalog output's during boot. The model of opto coupler was chosen because I could find them on ebay with din rail mounting for cheap...

Attachment 330926

[m_c]

I just connect a 24V relay to the SWE, then use a NO contact as part of the EStop loop.
The EStop loop on my lathe controls the main power contactors, so without the EStop loop being complete, nothing has power to move.

The 24 and 5V supplies are powered before the main contactors, so all the logic remains active during an EStop.

[GORDYKD]

Thanks for all the replies. I will be modifying the control circuits to incorporate these safety measures. The big challenge will be convincing the designer/builder that it is actually his responsibility to do this and cover the cost, as well as make changes to his way of thinking about control schemes.

[Al_The_Man]

The big challenge will be convincing the designer/builder that it is actually his responsibility to do this and cover the cost, as well as make changes to his way of thinking about control schemes.

Just quote to him NFPA79, Electrical Standard for Industrial Machinery, and NFPA70 or NEC, National Electrical Code.
Al.

[GORDYKD]

He still doesn't get it.

Below is a little of the latest correspondence.

Been three weeks since he promised to send additional components to correct some of the issues.
I have finally ordered all the components needed to get this machine to INDUSTRY ACCEPTED standards, not HIS IDEA of acceptable.

************************************************** ****************************************
Hi Tom,

I am still waiting on the relay from my supplier and expect it today or tomorrow. It is simply to ensure the spindle does not turn on start-up and has nothing to do with the estop. As I mentioned a month ago another way around this unwanted spindle turning was to power up the control system before powering up the machine. If you started the system each morning in this way there would be no issue with the spindle.

When I spoke to Kent last week I was under the impression he would take care of the estop wiring once I sent him an additional block for the cabinet estop switch. It is basically running the 2 power lines from the disconnect switch to the estop and then back to the breakers, as per the diagram I sent you.

I don't have a problem paying him for the repair work, but I do have a problem paying for someone to reverse engineer the system to ensure it meets their expectations. The original installation and connection costs were never part of my responsibilities.

I will send the relay and switch block once the relay comes in. An alternative to the switch block would be to replace the estop with a double throw one which Kent's company or any local automation store would probably have on the shelf. Let me know if this option works better for you.

With best regards,

************************************************** **************************************

On 8/22/2016 5:06 PM, Kent wrote:
David,
In response to:
“I don't have a problem paying him for the repair work, but I do have a problem paying for someone to reverse engineer the system to ensure it meets their expectations. The original installation and connection costs were never part of my responsibilities.”

Your control circuit is lacking the necessary components to be considered safe by even a far stretch of the imagination. My insistence on correcting this is not so much my expectations, but those of every safety certifying body in the modern industrial world. Not adhering to the widely practiced standards is not only risking the safety of the operators, but it is putting you in severe legal jeopardy should a serious event occur. It IS YOUR RESPONSIBILITY as a manufacturer. I’m very certain that CSA, NEC, OSHA and IEC would all totally agree with my position on this.

You would do yourself a favor by checking into the IEC 61508 Safety Standards for systems associated with electrical, electronic and software-based safety-related systems. It should be in your personal library.

IEC Search | Site search

For United States regulatory info see NFPA79, Electrical Standard for Industrial Machinery, and NFPA70 or NEC, National Electrical Code. Any equipment imported to the U.S. should meet these specifications.

Sincerely,
Kent

************************************************** ************************************************** ***********************
From David on 8-23-2016

Kent,

I was referring to financial responsibilities for commissioning the machine. Tom's note gave the impression the hours are piling up and I need to understand what these billable hours are. As we discussed, there is an issue with the Estop disconnect on the cabinet which should have been wired as per the drawing I sent. This will be corrected with a change to the primary wiring through that switch. I have worked with many machine builders over the years and the balance of the system is built with generally accepted control methods. The logic-based pendant wiring is often used to allow low voltage where the wiring may be vulnerable to damage from falling objects, such as the pendant.

Metal spinning is itself a very dangerous operation and my goal was to develop a system to help make it safer for operators. Is it perfect? Obviously not. Are we helping to make metal spinners safer? I believe yes, and with every unit produced fewer hand spinners are at risk.

These machines are sold with the understanding that the purchaser will have to read through the manual and familiarize themselves with the operation. Often new owners will plug these machines in, turn them on and start pushing buttons. This obviously will lead to problems with runaway machines. The procedures in the manual need to be closely followed for proper operation.

I understand that you and Tom have probably spent some time learning the system. The cost for this time is the purchaser's responsibility and is never included in our pricing. This is something that is explained to the purchaser when the pricing is established.

I spoke yesterday with a trusted electrical engineer and he agreed that because the control system for the LaBlond machine is unknown to us, the safest method for startup is to power up the control system and follow that with power up of the LaBlond once the controller is running and online. Given this, I ask that you please start the machine in this manner. This will resolve the issue of the spindle turning on startup.

As for the Estop, do you need me to send you a switch with a NC double throw for the cabinet, or can you source this locally?

Regards,
David
********************************************

[xjdubber]

He or they obviously do not have much experience building a proper control system. No matter whether its a metal spinner or a conveyor E-stop circuits need to be done properly. Metal spinners.... yup have one deformed finger because of one them. I have done two retrofit to Denn spinners modeling them after Denn's replay controller using Omron plc's. These were and still are hydraulic.