Thread: NC programming: going from cassette to CD.

I am running an Overbeck 600I ID/OD grinder with an 'Overbeck' NC control. Our programs are saved via a cassette tape backup system. The machine has no internal memory. When we perform a setup we 'play the tape' that corresponds to the part we are setting up. Since we are using old school cassette tapes I thought it would be a 'no brainer' to put everything on CD. I started out by connecting the 'audio' output of the NC to my laptop and used Sound Forge to capture the program and saved it on the hard drive. To test whether the NC could listen to something other than an old cassette player I hooked the 'audio' input of the NC to my laptop and replayed the program back to the NC. It worked fine. I then spent several hours collecting each program one at a time by playing the tape to the NC then sending it back from the NC to the laptop. Again, I tested the data by randomly playing a program from the laptop to the NC and everything worked fine. My next step was to burn the audio to a blank CD and play it back from a portable CD player. I could not get any programs to successfully load from the CD player to the NC. If I use headphones I can hear the programs so I know that something is on the disk. I tried a second portable CD player and still no luck. I then thought that I had a bad disk and burned a second CD. Still no luck. I then tried to play the CD from the CD player in my laptop and it worked fine. Next I started looking at the specs on the cassette player and comparing them to the specs on my CD player. Both CD players have far better signal to noise ratio and frequency response specs than the cassette deck. I can't figure out why I can successfully send a program to the NC with a cassette and/or with the laptop but not with a CD. I also tried using an MP3 player and a digital voice recorder and neither worked. Can anybody help me make this work?
Thanks,

PR

Never heard of an "audio" memory storage for code.

???

How long can a grinding program possibly be?
Couldn't you just copy by hand to the disk as required?

Any chance of by-passing the disk and going strait to USB memory stick or the likes?


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I am Ox and I approve this h'yah post!

Is this for real? I had no idea such a thing existed. What does it sound like with headphones? Fax machine?

[QUOTE=Ox]
Couldn't you just copy by hand to the disk as required?
[\QUOTE]

Not sure what you mean here? The machine has no 'disk' or any type of internal storage.

Originally Posted by Ox

Any chance of by-passing the disk and going strait to USB memory stick or the likes?

No. The machine and it's control were built back in 1989 and haven't been updated... ever.

Originally Posted by Belding

Is this for real? I had no idea such a thing existed. What does it sound like with headphones? Fax machine?

A fax machine is a fair (not precise) analogy and/or telephone internet connections when you would hear your modem dialing and connecting.

I'm just making a hudge guess here...but I think what you might be running into is different formats between what a cassette uses to process sound and what a CD uses.The word might be codek?
I'm thinking that using Sound Forge you captured it in it's original analog mode,when you are using the CD or any other device it converts it to digital which the machine has no idea what to do with.

My guess is you are stuck with the laptop as the only way to store the audio files in thier original format.
Maybe there is a program like Sound Forge you have that will allow you to play a CD which is digital and convert it back to analog and into machine so you can back up files on the CD?
If not I suppose what ever format the audio file is in when burnt to a flash drive will play back in the same format once uploaded back to PC.

Originally Posted by IronReb

I'm just making a hudge guess here...but I think what you might be running into is different formats between what a cassette uses to process sound and what a CD uses.The word might be codek?
I'm thinking that using Sound Forge you captured it in it's original analog mode,when you are using the CD or any other device it converts it to digital which the machine has no idea what to do with.

My guess is you are stuck with the laptop as the only way to store the audio files in thier original format.
Maybe there is a program like Sound Forge you have that will allow you to play a CD which is digital and convert it back to analog and into machine so you can back up files on the CD?
If not I suppose what ever format the audio file is in when burnt to a flash drive will play back in the same format once uploaded back to PC.

Thanks for the reply but I don't think this it the problem. When I connect the NC to the CD it is only to the CD player's headphone jack. The NC is only 'hearing' the sounds and converting those sounds to usable data. The CD player isn't really transmitting and digital data just noise.

A couple ideas:

1. Could the impedance of the NC unit be too high for the portable players to recognize?

2. Is the "signal" mono or left and right? Are you using the same cable for the computer and portable devices?

Originally Posted by Belding

A couple ideas:

1. Could the impedance of the NC unit be too high for the portable players to recognize?

2. Is the "signal" mono or left and right? Are you using the same cable for the computer and portable devices?

1. Not sure. The current playback method is from an old RCA cassette player.

2. The signal is mono - left channel only. Using the same cable. The cable 3.5mm jack and the wire is soldered to the machine's board and comes out from the cabinet through a door on the control panel.

It might be worth it to borrow an O-scope and compare left channel amplitudes from the computer and CD player.

Was the CD player plugged in (110v) or running on batteries? What about the laptop? Just wondering if there was some strange ground isolation thing going on.

Originally Posted by Belding

It might be worth it to borrow an O-scope and compare left channel amplitudes from the computer and CD player.

Was the CD player plugged in (110v) or running on batteries? What about the laptop? Just wondering if there was some strange ground isolation thing going on.

Interesting idea. The cassette deck is plugged in. There is an AC plug that is also soldered to a board in the machine and we gain access by using the same door that the audio cables use. The laptop has worked successfully with and without AC power. The CD player has always been using battery power.

My guess is its the way the sound is written to cd. A compression format is used, its very diffrent to the analogue format a tape is written in. You could try a mp3 player easily enough and see if its any better. Other wise you may have to stick to a analogue source. Gramophone maybe?

I agree with "if the laptop works, use the laptop." Your basic POS laptop with who-cares-how-old operating system, used only for playing back the audio files, and never on the internet, would cost about $5 at a garage sale. Make sure you can plug in an external monitor and keyboard, and treat it like the cassette player... don't use for anything else.

If you want to dive in further, a good scope is necessary to guard against wasting your time. Use it to compare waveforms while the cassette deck is connected to the machine, not just sitting on the bench.

Take a look at some online forums for the TRS80 computer, and other early devices. These used cassettes for data storage, and there's doubtless been some research into tape replacement. You're looking for audio interface projects, rather than 'adding a disc drive' projects.

On the CD, you might try turning the headphone level control up or down to see if it's level-dependent.

Good luck!

Chip

Its real. Once upon a time I programmed a German grinder, (can't remember the name but it started with a "W" and had about 14 letters), that used the same system.
i_r_

Yep.....not that unusual depending on the part of the world you are in.
Early CNC Deckels with the Dialog Controls use the tape cassette for program storage/reloading. Works fine for storage ...just can't edit off line.

As to your problem on loading a program from CD....i think it is a matter of format. CD's use digital compression something your tape does not....think the control cant read the signal.
Sounds the same to your ear, but not to the machine.

Cheers Ross

Originally Posted by AlfaGTA

As to your problem on loading a program from CD....i think it is a matter of format. CD's use digital compression something your tape does not....think the control cant read the signal.
Sounds the same to your ear, but not to the machine.

Cheers Ross

Yeah, but the CD worked from the computer.

Thanks for the reply but there is no compression used. The files are pulled from the NC to the PC and saved as uncompressed .WAV files then burned to CD. Also, the programs will load if I play the CD from the CD-ROM in the laptop but the program will not load if I use a portable CD player.

Originally Posted by Chip Chester

I agree with "if the laptop works, use the laptop." Your basic POS laptop with who-cares-how-old operating system, used only for playing back the audio files, and never on the internet, would cost about $5 at a garage sale. Make sure you can plug in an external monitor and keyboard, and treat it like the cassette player... don't use for anything else.

Can't use laptop. Need to make this as easy as possible for other operators.

Originally Posted by Chip Chester

On the CD, you might try turning the headphone level control up or down to see if it's level-dependent.

Played with the volume for hours. Didn't help.