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Mikron Haas VCE 750 communication issues over RS-232 link

allenp

Aluminum
Joined
Jul 13, 2015
Hello,
we've got this machine that is acting weird right now, we have 2 laptops (just bought another one for reserve today) which we are using for transmiting programs to machines.
We've also got 4 fanuc machines also using RS-232 for communication and transfering of programs to and from machines.

On old laptop everything works just fine on every machine, on this new one every fanuc machine works fine and on this Mikron Haas VCE 750 I can send programs from machine to laptop, no problems, but when I try to send program from laptop to machine it says RS-232 empty program every time I try.

I've tried just now to once again send same program using older laptop and it will work no problem.

So it seems to me either there is something weirdly wrong with this new laptop or with haas machine.

Cable is not a problem since we can use this older laptop both ways no problem.
Also every time when I press send on new laptop, during transmission of program I see some weird <DC><DC> characters in between G-code lines. What is that?

What is weird also is that when I use older laptop (which normally work as it should) and press send on laptop to send a program, but on the machine end I haven't pressed receive I get same weird <DC><DC> characters during transmission of program and after I've done that I press receive on machine and then send on laptop it will recreate the same alarm "RS-232 empty program" on machine.
If I now, after that, reset machine alarm and repeat process of sending from laptop to machine, it will work this second and every other time. Only when I don't press receive on machine and press send on laptop it will act up like that.

I've tried setting up communication ports on newer laptop and on machine, set parity to none, but nothing helped.
Even the simplest program:
%
O1000
M30
%
wont go through.

What could be the problem?
Thanks for any advice in advance.
 
The <DC> characters are "device control" characters, also called xon/xoff. They are used to implement software handshaking. Normally, they are handled in hardware, and you should not see them on your screen.

I can't tell for sure where you are seeing the control characters, but if you configure the new laptop to use software hand shaking (without changing anything else), your problem might go away.

See: https://en.m.wikipedia.org/wiki/Software_flow_control
 
I did try using software flow control and those characters did go away, but the problem still existed, that is, I still got the alarm 418 and 411 on machine

I was seeing control characters in between G-code while transmission was ongoing.

For example:

G01 X150. F1000
<DC3><DC3><DC3><DC3><DC3>
Y150. F500.
Z-12.
<DC3><DC3>
...
 
G01 X150. F1000
<DC3><DC3><DC3><DC3><DC3>
Y150. F500.
Not sure what to say about the "break" error message, but I think it suggests that one of the hardware lines (DTR/DSR or RTS/CTS?) is getting turned off by your PC.

But the DC3 codes tell me that your handshaking is just not working. DC3 is xoff, which means "transmission off", and on my machine, I get ONE xoff after each line. I only get one because my setup stops sending until it receives an xon to turn the data transmission back on. If you get 5, it means your PC is ignoring the xoff characters, and continues to send in spite of the first xoff.

You don't say how you are generating the rs232 from the laptop (usb to rs232 converter?), or what the operating systems are on the two. RS232 is very poorly supported on modern operating systems, so any operating system difference could be the reason the new laptop doesn't work. I would guess that software handshaking is less well supported than hardware handshaking, but I don't know for sure.

This problem is complicated by the fact that one laptop DOES work. If it wasn't for that, I would go all-in on hardware handshaking. Get a pass-thru LED connector for your rs232 cable, so you can see the state of the hardware handshake lines. Make sure the cnc is set for hw handshaking, and the same on your new laptop. When you hit "receive" on the cnc, you should see the CTS (clear to send) line change state. If you get that far, you should be able to wrangle the PC into properly honoring the CTS handshaking line and send data only when CTS is asserted.

It is perfectly possible to have both hw handshaking and sw handshaking turned on at the same time. Your cnc clearly has sw handshaking turned on. Turn on hw handshaking as well; it might solve your problem without making the "good" laptop fail. Tell us what you are using between the laptop and the cnc, and tell us the operating systems of both laptops. And get an LED pass-thru device so you can see the hardware handshaking signals from the cnc. I don't have one, but several people have recommended units on other PM threads. This is an example, but I don't know whether you use 9 pin or 25 pin connectors. Other versions like this allow you to disconnect/reconfigure lines and force them high or low.
 
Hello,
we've got this machine that is acting weird right now, we have 2 laptops (just bought another one for reserve today) which we are using for transmiting programs to machines.
We've also got 4 fanuc machines also using RS-232 for communication and transfering of programs to and from machines.

On old laptop everything works just fine on every machine, on this new one every fanuc machine works fine and on this Mikron Haas VCE 750 I can send programs from machine to laptop, no problems, but when I try to send program from laptop to machine it says RS-232 empty program every time I try.

I've tried just now to once again send same program using older laptop and it will work no problem.

So it seems to me either there is something weirdly wrong with this new laptop or with haas machine.

Cable is not a problem since we can use this older laptop both ways no problem.
Also every time when I press send on new laptop, during transmission of program I see some weird <DC><DC> characters in between G-code lines. What is that?

What is weird also is that when I use older laptop (which normally work as it should) and press send on laptop to send a program, but on the machine end I haven't pressed receive I get same weird <DC><DC> characters during transmission of program and after I've done that I press receive on machine and then send on laptop it will recreate the same alarm "RS-232 empty program" on machine.
If I now, after that, reset machine alarm and repeat process of sending from laptop to machine, it will work this second and every other time. Only when I don't press receive on machine and press send on laptop it will act up like that.

I've tried setting up communication ports on newer laptop and on machine, set parity to none, but nothing helped.
Even the simplest program:
%
O1000
M30
%
wont go through.

What could be the problem?
Thanks for any advice in advance.

Sounds like a windows update and always trust Microsoft.
 
Not sure what to say about the "break" error message, but I think it suggests that one of the hardware lines (DTR/DSR or RTS/CTS?) is getting turned off by your PC.

But the DC3 codes tell me that your handshaking is just not working. DC3 is xoff, which means "transmission off", and on my machine, I get ONE xoff after each line. I only get one because my setup stops sending until it receives an xon to turn the data transmission back on. If you get 5, it means your PC is ignoring the xoff characters, and continues to send in spite of the first xoff.

You don't say how you are generating the rs232 from the laptop (usb to rs232 converter?), or what the operating systems are on the two. RS232 is very poorly supported on modern operating systems, so any operating system difference could be the reason the new laptop doesn't work. I would guess that software handshaking is less well supported than hardware handshaking, but I don't know for sure.

This problem is complicated by the fact that one laptop DOES work. If it wasn't for that, I would go all-in on hardware handshaking. Get a pass-thru LED connector for your rs232 cable, so you can see the state of the hardware handshake lines. Make sure the cnc is set for hw handshaking, and the same on your new laptop. When you hit "receive" on the cnc, you should see the CTS (clear to send) line change state. If you get that far, you should be able to wrangle the PC into properly honoring the CTS handshaking line and send data only when CTS is asserted.

It is perfectly possible to have both hw handshaking and sw handshaking turned on at the same time. Your cnc clearly has sw handshaking turned on. Turn on hw handshaking as well; it might solve your problem without making the "good" laptop fail. Tell us what you are using between the laptop and the cnc, and tell us the operating systems of both laptops. And get an LED pass-thru device so you can see the hardware handshaking signals from the cnc. I don't have one, but several people have recommended units on other PM threads. This is an example, but I don't know whether you use 9 pin or 25 pin connectors. Other versions like this allow you to disconnect/reconfigure lines and force them high or low.
SeeFair, firstly, thank you very much for your extensive explanations...

Second, both laptops use Windows 7.
Third, I'm not using any USB2RS232 converter, just the RS232 cable, because both laptops have 9pin RS232 ports and on the CNC there is 25pin RS232 port, so the same is on cable we are using. We have multiple cables, longer and shorter and I have tried all of them, none of them work with newer laptop, but all of them work on older laptop.

Fourth, I'm using Cimco Edit, I think those signals are shown there while transmiting/receiving, so I will check for CTS and tell you what it's showing.

Fifth, how do you know cnc is using SW handshaking? On older laptop in Cimco, same as in newer laptop, under DNS setup hardware handshaking is selected and it works on older laptop like that, but not on newer laptop.

What is puzzling to me also, why is everything ok on Fanuc machines?

Why is there no problem with handshaking and communication?

There are 3 fanuc machines and I have tried on all of them with this same cable and same new laptop and setup and everything works fine there.

That would mean there is something wrong on the machine, but how is something wrong there when on older laptop everything works fine and also I can send program from cnc to laptop using that new laptop and same cable?
 
Here is the update, the only difference I see is that on new laptop both RX and TX are active
 

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From a web search, this is a Mikron with a Haas controller. The one I found says the control is from 1993 so likely similar to my '91 VF-1. On the laptops, check the Tx buffer size under the Device Manager. On mine, it has to be set down to 1. The older controls have a very limited buffer size and a new computer will over run the buffer before the machine can send a stop signal. I use hardware handshaking as it is more reliable than software. I can transmit at 38.4k.
 
That's really good information.
That would mean there is something wrong on the machine, but how is something wrong there when on older laptop everything works fine and also I can send program from cnc to laptop using that new laptop and same cable?
Your cnc has a funky mode where it responds to rs232 characters with xoff. That may or may not be affected by parameter settings. You can get it into that mode with either the old laptop or the new laptop. Your old laptop is somehow different because it puts the cnc into receive mode every time except the first. So something is different about the new laptop.

check the Tx buffer size
I'm with magno on this. I don't know what other configuration options you have.

I would still get a 25 pin LED pass thru. The information you provided is great, the software looks great, the signals look great. But what are the actual signal levels at the cnc
 
From a web search, this is a Mikron with a Haas controller. The one I found says the control is from 1993 so likely similar to my '91 VF-1. On the laptops, check the Tx buffer size under the Device Manager. On mine, it has to be set down to 1. The older controls have a very limited buffer size and a new computer will over run the buffer before the machine can send a stop signal. I use hardware handshaking as it is more reliable than software. I can transmit at 38.4k.
Thanks, but it didnt work. Still the same .

Why are both Tx and Rx active while transmitting program to machine?
 
I have just tried changing setting in RS-232 from XON/XOFF to RTS/CTS and it worked...for just one time.
It transfered program to machine successfully, then I sent program back to computer just to see if it still works too.
And I've tried sending from PC to machine one more time...here we go again. Same as before, alarm occurs.

Then I've tried changing back to XON/XOFF and again nothing.
Again to RTS/CTS, still nothing...
Tried some other settings on the machine and laptop, nothing.
So I've set it as it was originally (settings which work normally on other laptop) and I still don't know what happened that one time that it went through to machine...
 
Unless someone has an identical setup, this is only going to get fixed by futzing around with it, which is what you are doing and is normal for rs232.

Who knows what the "it worked once" symptom means? Maybe an intermittent connection? But you've tried a bazillion cables, so if there's a cable problem, look for it at the new laptop: are the pins all happy on the new laptop's 9 pin connector?

Or maybe it means that the new laptop sometimes has the right hw handshaking, sometimes not. Those very informative displays on your laptop, that show TX/rx levels, and the handshake levels: those are just icons indicating what your cimco (or whatever) software thinks it set the handshake lines to. It set those lines via a software driver for Windows7. There's potentially bugs in both softwares. Buy an led Indicator/tester and hang it on the line next to the machine so you can actually see the state of the hardware handshake at any time. You can leave it on the cable forever, so you'll know where to find it and the blinking lights will keep you company. You really have to know that the laptop is presenting the proper be handshake levels at this point.
 
Or maybe it means that the new laptop sometimes has the right hw handshaking, sometimes not. Those very informative displays on your laptop, that show TX/rx levels, and the handshake levels: those are just icons indicating what your cimco (or whatever) software thinks it set the handshake lines to. It set those lines via a software driver for Windows7. There's potentially bugs in both softwares. Buy an led Indicator/tester and hang it on the line next to the machine so you can actually see the state of the hardware handshake at any time. You can leave it on the cable forever, so you'll know where to find it and the blinking lights will keep you company. You really have to know that the laptop is presenting the proper be handshake levels at this point.
Ok can you sugest some led indicator/tester which we should buy?
New laptop has Windows 7 Professional service pack 1 and old laptop has Windows 7 Ultimate service pack 1.
I don't know what the difference could be in those drivers....
Everything is just weird to me with this problem.

Unless someone has an identical setup, this is only going to get fixed by futzing around with it, which is what you are doing and is normal for rs232.
Seems to me it is going to be like that exactly :(

Who knows what the "it worked once" symptom means? Maybe an intermittent connection? But you've tried a bazillion cables, so if there's a cable problem, look for it at the new laptop: are the pins all happy on the new laptop's 9 pin connector?
Yes I've tried numerous cables, it is the same for every one, even shortest one.

New laptop has 2 com ports, they both look normal and ok, I've tried communicating with both ports on that laptop, it is the same.
 
New laptop has Windows 7 Professional service pack 1 and old laptop has Windows 7 Ultimate service pack 1.
That could easily be the difference. Or the driver.


Ok can you sugest some led indicator/tester which we should buy?

. This is an example, but I don't know whether you use 9 pin or 25 pin connectors. Other versions like this allow you to disconnect/reconfigure lines and force them high or low.
Click on the word "this". They don't get simpler than the first one, but if you find that you want to strap RTS high (or something similar), then you want the second.
 
Just to throw this out there.
When you start to get multiple machines, and multiple workstations it is probably better to get a server computer that acts as the hub machine,
connecting all the machines and computers together through it.

That way your not trying to get new computers to work with machines.
 
I don't want to sound like I'm just throwing random stuff at the wall but, about a year ago, I was troubleshooting a misbehaving rotary box on a 2004 VF-2. I must have read every RS-232 Haas post on the web in that month or so. Somewhere in all of that, I do remember at least one who had a bad serial chip on one of the boards. There was also one that had a problem with the physical port on the side of the machine and the ribbon cable going to it.

Some of us picture our own pampered machines in our heads and we aren't looking at the horrible physical condition some machines are in after so many years. It could be whiskers of corrosion bridging pins. Someone may have been in there for a battery replacement years ago and pinched one of those ribbons against the sheet metal, or any number of other possibilities. Opening up the cabinet and pulling the board stack one at a time and doing some physical inspection could make some sense.

If none of those show anything, I'm still (like others) suspicious of overloading the input buffer.
 
That could easily be the difference. Or the driver.





Click on the word "this". They don't get simpler than the first one, but if you find that you want to strap RTS high (or something similar), then you want the second.
I have 25 pin connector on machine side, this looks like its 9 pin.
 
That could easily be the difference. Or the driver.
Sometimes you are screwed .... Silicon Graphics 3000 series machines had a firewire driver. Firewire worked really well with them ... but only with the TI chip and oddly enough, adaptec had a couple versions of the same card with supposedly the same chip (but different revisions ?) -- the blue card worked, the red card did not.

That doesn't happen as often with really mainstream stuff but serial ports are getting to be kind of arcane. RS stands for 'recommended standard', not all companies implement everything correctly :( Look in your hardware inventory, I bet the chips between the two laptops are not the same.
 








 
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