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No door interlocks - Siemens 808D Advanced Mill controller

Das_Wookie

Aluminum
Joined
Jan 11, 2008
Location
Austin, TX
I recently purchased a VMC from a machine builder in China. Overall the machine is great. One problem tho is that they didn't install any door interlocks. Looking through the commissioning manual, I'm seeing support for it on the digital I/O OUT, on the X200 connector - Pin 8. What I'm unsure of however, is how to wire this up. I figure I can either put a NO/NC roller contact switch on it, or better still an inductive sensor, but first I need to figure out how to wire ANYTHING up to the controller. I talked with the builder, and they acknowledged that they don't install door safety interlocks normally, and because I hadn't requested it, they didn't install them. Big deal. I figure I can retrofit some on the machine... if I can only figure out where and how to wire it up!

Anybody have any experience with wiring on the 808D (or 802D, 820D, or 840D) controller that could walk me through what needs to be connected from where to where to make this happen?

It LOOKS like I just need to come out of X200, pin 8, go to a NO switch, and then connect the closed part to ground back on pin 10 of the x200 - M - External Ground point.

Here's the commissioning manual, in particular, page 44:
https://cache.industry.siemens.com/...1/808D_Commissioning_Manual_0815_en_en-US.pdf

808D-Door_Interlock.jpg

808D-1.jpg

808D-2.jpg

I'm a bit... pensive... to go mucking about with the wiring on my new machine... but I have GOT to get safety door interlocks enabled if I have ANY chance of my insurance company not hanging me out to dry in the event of an accident, door safety interlock related or not.
 
... One problem tho is that they didn't install any door interlocks. ...

Man, that's a problem I would like to have!
Tell you what, If you can unwire it from my Mori and make it functional without it, you can have the switch AND the locking mechanism.

Serious question though, if the equipment did NOT come with certain measures, does that mean that the insurance co. can still ding you for it?
And, along the same lines, if the machinery SHOULD be up-to safety requirements and it isn't, then how did it end up here in the first place?
Does it have a UL approval even?

Not trying to be a jerk, just asking.
 
I'd like to add in here without trying to sound like a jerk too.

If you have to ask here for advice on integrating a door interlock system, you should not be doing the install. Just the fact that you state "... I figure I can either put a NO/NC roller contact switch on it, or better still an inductive sensor.." shows you are not knowledgeable in the design and required hardware for a safety system that is compliant with any standards. If you install a non-compliant safety system and someone gets hurt, your insurance company is not going to help once they figure that out. OSHA requires door interlock systems comply with an ANSI standard. Before you slap together something you should get those standards and learn up on the subject.
 
This is going to be an expensive lesson. My first question is how did a machine tool get imported into the US without meeting the safety standards?

Second, the standard requires monitored, locking safety switches, a roller switch absolutely will not do. By monitored, that means the switch has dual channels and they are monitored for switching time between the two channels. Not sure if it is part of the new standard yet in the US, but all machines we have been getting from Europe also have RFID keys, meaning the key for the switch must match the switch. (no more spare keys laying around, they won't work.)

If you do not make the machine tool builder put this stuff on, you for certain need to get an Electrical Engineer that is well versed in Machine Tool Safety to do this work for you. Your insurance will drop you like a rock if they find out you didn't. It will be cheaper to have the machine tool builder to do it. It also is a good idea from a liability standpoint. If they do it, they are in the lead for liability, not you. If you do it or have it done, the buck still stops with you.
 
The machine was a custom build and the Siemens 808D control is for custom / prototype machinery.

Honestly tho, if y'all don't have experience with with Siemens controllers, then your comments aren't useful. I was seeking input from someone who has programmed and wired a Siemens controller. That is all.
 
The machine was a custom build and the Siemens 808D control is for custom / prototype machinery.

Honestly tho, if y'all don't have experience with with Siemens controllers, then your comments aren't useful. I was seeking input from someone who has programmed and wired a Siemens controller. That is all.

Well I, for one, do have experience with the new Siemens controllers, as well as Fanuc, and a couple other CNC controllers, as well as about every brand of Industrial PLC out there. I actually work in new Product Development for the Automation Division of a Machine Tool Builder and I can say unequivocally that you've received nothing but gracious and helpful feedback from this post, despite apparently buying a brand new machine tool from a builder who displayed a shocking amount of ignorance in US/Euro Safety standards. For the record, the 808D isn't 'specialized' for prototype machines - it's an entry level control for basic milling and turning applications.

I have no idea why you're even considering doing this yourself, other than the fact that you bought a prototype machine from someone in China, and they delivered you something that wasn't finished/safe, which they now want nothing to do with. This is their problem, unless of course your spec for the machine didn't include a section on machine safety? My mind boggles at how this is even possible. Even the bad Chinese machine builders typically have a half-baked 'safety' circuit on their machines. Maybe they used up all the built-in safety relays in the controller and cheaped out on not wanting to buy external safety relays?

I cannot say strongly enough how much you should listen to Tony and Vancbiker about this. If your biggest worry is honestly about insurance dinging you for not having a safety interlock on the door, you should be worried that they're going to ding you for not having the correct safety interlock on the door. Some random, easily defeatable switch doesn't cut it for safety interlocks.

To answer what I think your question was: no, you cannot just grab an open I/O point and wire a switch to it for anything related to machine safety and have it be considered 'safe.' It needs to run through the safety circuit, which as Tony stated, is redundant/monitored.
 
Well I, for one, do have experience with the new Siemens controllers, as well as Fanuc, and a couple other CNC controllers, as well as about every brand of Industrial PLC out there. I actually work in new Product Development for the Automation Division of a Machine Tool Builder and I can say unequivocally that you've received nothing but gracious and helpful feedback from this post, despite apparently buying a brand new machine tool from a builder who displayed a shocking amount of ignorance in US/Euro Safety standards. For the record, the 808D isn't 'specialized' for prototype machines - it's an entry level control for basic milling and turning applications.

I have no idea why you're even considering doing this yourself, other than the fact that you bought a prototype machine from someone in China, and they delivered you something that wasn't finished/safe, which they now want nothing to do with. This is their problem, unless of course your spec for the machine didn't include a section on machine safety? My mind boggles at how this is even possible. Even the bad Chinese machine builders typically have a half-baked 'safety' circuit on their machines. Maybe they used up all the built-in safety relays in the controller and cheaped out on not wanting to buy external safety relays?

I cannot say strongly enough how much you should listen to Tony and Vancbiker about this. If your biggest worry is honestly about insurance dinging you for not having a safety interlock on the door, you should be worried that they're going to ding you for not having the correct safety interlock on the door. Some random, easily defeatable switch doesn't cut it for safety interlocks.

To answer what I think your question was: no, you cannot just grab an open I/O point and wire a switch to it for anything related to machine safety and have it be considered 'safe.' It needs to run through the safety circuit, which as Tony stated, is redundant/monitored.

Have you wired up an 808D yourself? Yes, there is support for the built in safety interlock on the controller. It wasn't wired up. I'm looking at doing this because I want the safety interlock enabled. I'm conversing with the builder, but that dialog is agonizingly slow due to the timezone differences and the fact that I'm conversing with their english speaking sales team, not the Chinese speaking technical team... with all those messages filtered through the translation which makes things one hell of a lot of fun! {eyeroll}

So my desire to see it resolved is why I asked if anyone had any experience with commissioning one of these controllers and wiring them up. Plenty of people have put 808D, and before that 802D, controllers on machines themselves.

How did this happen, I don't know. An oversight perhaps. I'm trying to correct it.

What I DON'T need is being talked down to about a lack of an interlock. FFS I -=KNOW=- that's a problem. The controller supports it. I've found the section in the manual that describes the connections in the base milling config. If you look at the photos from the origional post, I've found the areas in the PLC where it's discussing the door interlock (which also mentions the light and chip conveyor), but... I don't have personal experience with commissioning one of these things.

I came here seeking help from someone who's perhaps dealt with wiring up one of these controllers and then the software side of things for configuring the PLC / commissioning the thing.

X200.8 is the base IO/Port for the door safety interlock. There's a white white wire with a label of Q0.6 connected to it. I traced this into the electrical cabinet, and found it connected to a relay, but was unable to determine where it goes from there. It doesn't appear to be being used for the door interlock, so is likely setup in a non-default configuration to be something for the tool setter, oiler, ATC, I dunno. Something else tho. There are other open ports in the controller. So I can either find an open port or re-assign the existing used one and put x200.8 back over to the door interlock. The controller has 4 sets of ports, with 10 connections on each. 8 are usable, the other 2 being for 24v in and ground. Not all of them are currently used.

I've wired up plenty of projects. I'm no stranger to a soldering iron, or coding computers or microcontrollers. I've never tackled a PLC, but there is a number of wizards in the controller for doing the configuration, as well as some Siemens PC program to do it as well. That's possibly the route I will have to go if I can't figure out how to configure it via the controller itself.

Lecturing me on safety of purchasing a machine that came without the interlock already enabled, isn't helping. Be helpful, or move along. Please.
 
You are terribly wrong here. The brand of CNC control has absolutely no bearing on the ANSI requirements for door interlocks.

Fine. You're right. I may as well just burn the machine to the ground. WTFF are you trying to accomplish here? I'm asking for help. Go lecture somebody else who isn't trying to fix their machine.
 
Man, that's a problem I would like to have!
Tell you what, If you can unwire it from my Mori and make it functional without it, you can have the switch AND the locking mechanism.

Serious question though, if the equipment did NOT come with certain measures, does that mean that the insurance co. can still ding you for it?
And, along the same lines, if the machinery SHOULD be up-to safety requirements and it isn't, then how did it end up here in the first place?
Does it have a UL approval even?

Not trying to be a jerk, just asking.

The controller supports it. It just wasn't wired up. I can't tell if the PLC is already commissioned for it and I just need to "connect the wiring" to get the functionality enabled, or if they commissioned the PLC / Controller and assigned the default IO Pin to another function. I'm not familiar enough with these things to really say. I traced the wire to the electrical cabinet, and it's connected to a relay. Said wires then disappear back into the bowls of the machine, and I'm not sure where they emerge again. I could tear the machine down and try and trace the wire to where it goes and figure out how it's currently utilized, or I could just say "OK, start anew, lets just run through the process and configure it how it will work" and never mind the existing wiring which I would rather not much about with anyway.

There is some way of connecting the 24v signal wire into the controller to enable the door interlocks. I'm not sure EXACTLY how to go about doing that tho, so figured I'd poke my head up on PM and see if anyone who's done an 808D controller install on one of their machines had any experience and recommendation.

Instead, I'm getting flack from the peanut gallery about how I'm apparently an idiot for purchasing a machine made overseas which didn't come with the interlock enabled already.
 
Door switches will be normally closed devices. If the PLC is all setup for switches and someone forgot to install them, this thing will be permanently stuck in a helpless state waiting for the switches to close.
 
Door switches will be normally closed devices. If the PLC is all setup for switches and someone forgot to install them, this thing will be permanently stuck in a helpless state waiting for the switches to close.

Good point. That eliminates the possibility that just MAYBE the Q0.6 wire I found run to the relay in the electrical cabinet isn't going to be wired in just without a switch connected to it... so it's got to be run to something else for sure then. Well, unless maybe they just connected it to the NC side of the relay. I am still trying to determine what the socket on the relay connections are. I suppose I could power the machine off and probe the connections safely to determine if it's connected to the NC side of the socket.

plc-3.jpg

Still searching for a schematic on the pinouts on the socket. I haven't noticed the relay ever toggle, and have been unable to find where wire 13 leads off to... but if I power the VMC off I could probe for NC or NO at least.
 
Fine. You're right. I may as well just burn the machine to the ground. WTFF are you trying to accomplish here? I'm asking for help. Go lecture somebody else who isn't trying to fix their machine.

You are the one that posted about needing a door interlock to satisfy the concerns of an insurer. Sure, any dumb fuck can ghetto rig something they call a "door interlock" but it's not going to satisfy an insurer if an accident investigation occurs. You've been given advice on how to do it correctly. Choose to listen or choose not to. Go ahead and ghetto rig up something. You now know what that makes you.
 
Second, the standard requires...

Tony, I don't know what the standards are.
Nor do I care!

What I care about is what I believe to be a safe environment for the person using the equipment and his/her brain.

Seriously? RF tags on a switch?

And on the note of "standards". Do you think a disruption of a light curtain should or should not disable a press ( stamping or forming ) on the upstroke?
At what point should common sense prevail?
 
Good point. That eliminates the possibility that just MAYBE the Q0.6 wire I found run to the relay in the electrical cabinet isn't going to be wired in just without a switch connected to it... so it's got to be run to something else for sure then. Well, unless maybe they just connected it to the NC side of the relay. I am still trying to determine what the socket on the relay connections are. I suppose I could power the machine off and probe the connections safely to determine if it's connected to the NC side of the socket.

View attachment 219210

Still searching for a schematic on the pinouts on the socket. I haven't noticed the relay ever toggle, and have been unable to find where wire 13 leads off to... but if I power the VMC off I could probe for NC or NO at least.

That is not a safety relay, it is a standard miniature general-purpose "ice cube" relay. The door circuit requires a safety relay, which has built-in redundancy and is a requirement for safety circuits. This also means they possibly used the output / inputs for the safety circuit for other items and the logic in the controller will have to be modified. I'm sorry, but this is not as simple as hooking up some wires to a switch. Also, you are looking at the output side of the circuit, which is used for the door lock solenoid. What is hooked to the input side of the safety circuit contacts on the 808?

As I said above, it's not as simple as it seems. Yes, the inputs / output terminals may be there, but that doesn't mean that they actually DO anything.

In addition, if you do "wire up" a door safety switch and it doesn't meet code or the PLC code isn't there or correct and someone gets hurt, YOU personally can be held liable -- not just civil, but there is potential criminal liability also. This is not something to muck around with and half-ass - I urge you to get professional help for this situation as you obviously do not have enough information available about how the controller is set up on this machine.

I've been involved in a lot of custom machine builds (well over 100) with Siemens (and several others), though never an 808 specifically, but the type of control in this situation doesn't really mean all that much until you get to the programming.
 
That is not a safety relay, it is a standard miniature general-purpose "ice cube" relay. The door circuit requires a safety relay, which has built-in redundancy and is a requirement for safety circuits. This also means they possibly used the output / inputs for the safety circuit for other items and the logic in the controller will have to be modified. I'm sorry, but this is not as simple as hooking up some wires to a switch. Also, you are looking at the output side of the circuit, which is used for the door lock solenoid. What is hooked to the input side of the safety circuit contacts on the 808?

As I said above, it's not as simple as it seems. Yes, the inputs / output terminals may be there, but that doesn't mean that they actually DO anything.

In addition, if you do "wire up" a door safety switch and it doesn't meet code or the PLC code isn't there or correct and someone gets hurt, YOU personally can be held liable -- not just civil, but there is potential criminal liability also. This is not something to muck around with and half-ass - I urge you to get professional help for this situation as you obviously do not have enough information available about how the controller is set up on this machine.

I've been involved in a lot of custom machine builds (well over 100) with Siemens (and several others), though never an 808 specifically, but the type of control in this situation doesn't really mean all that much until you get to the programming.

I intend to wire it up correctly. The photo was just what the STANDARD x200 pin 8 ended up being connected to. I'm positive it's NOT going to a door safety interlock, because there aren't any on any of the doors.

My intent is to use a set of inductive sensors and connect that to the two side doors, the two front doors, and possibly also the two doors on the back of the machine one being the electrical cabinet and the other being the access to the coolant pump, lubrication pump, and pneumatic controls for the ATC.

I made some progress with the machine builder yesterday. They have apologized for the oversight on the door interlocks, and are updating the PLC project to use the feature. I'll then install and setup 3 wire inductive sensors on all the doors I want monitored, and beingo... the machine will alarm out if one of the doors is opened. I'll still be able to bypass the door interlock if needed for testing or in case I have material in the machine that extends outside of the enclosure, but my primary worry of being able to open a door and not have the machine alarm out should be handled.

My concern over the insurance company was mentioned as a side note to the concern about the machine not having a door safety interlock. My primary business is motorcycle parts, so insurance concerns is high on my normal checklist of concerns. I will pretty much be the sole operator of the machine, tho I may possibly have someone else run it in the future, maybe. I know -=MYSELF=- well enough to know that I may at some point in the future yank a door open to deal with something without first shutting everything down, and want the machine to safe itself in the process if I didn't do it myself first. That's decades of manual machining where if I'm not physically turning handles only the spindle is turning, and it's going to take a while for my lizard brain to adjust to button pusher land of CNC Operator. ;)

Anyway, progress is being made. It's just agonizingly slow and I was thinking that I might have possibly been able to resolve the problem without the need of assistance from the machine builder. Clearly that's not the case.
 
So where or what does the relay in the picture do??? I know, it would be hard to tell because machine is probably under a constant "no go" "E-Stop", because the controller is waiting for a closed circuit signal from the safety relay.

For your machine to pass any safety standard, through a knowledgeable insurer, you have to wire the doors up to a safety relay. They are expensive and the newer the machine the harder it becomes to defeat the safety systems.

Who is your machine builder. Just curious.
 
So where or what does the relay in the picture do??? I know, it would be hard to tell because machine is probably under a constant "no go" "E-Stop", because the controller is waiting for a closed circuit signal from the safety relay.

For your machine to pass any safety standard, through a knowledgeable insurer, you have to wire the doors up to a safety relay. They are expensive and the newer the machine the harder it becomes to defeat the safety systems.

Who is your machine builder. Just curious.

I'm not sure where that relay goes. I SUSPECT it goes to the lubrication pump, but I'm not sure.

The machine currently runs, it's missing the interlock which concerns me because I know it should be there, and was VERY surprised to see it was not installed.

I'm unfamiliar with the type of relay you are describing. Can you point me in the right direction of what I should be looking for?

This machine is basically a high end hobby level VMC, with a 5.5kw BT40 8k spindle. Machine weighs 8050#, so it's a huge step up from a Tormach 1100, but you might consider this machine a Haas VF2 clone, of a sort. I've been running my parts on an X-Carve, but it was time to upgrade! I priced out a Tormach, then took that budget amount and went shopping... I purchased it from Runfa, and had previously purchased another machine (a 40kg power hammer) from them. I'm very impressed by the machine and its capabilities. They made a mistake with the door interlock, and it's getting rectified.
 








 
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