Converting recorded audio data to ladder

I am trying to help someone with an old Gould PC0085. They have sent me an audio file (.wav) that was recorded from the output of a PP0105 programmer. I have the SW85 software and would like to take the recorded audio data and somehow get into a usable file to generate a ladder printout with the sw85 software.
Is there anyone on the forum that has done anything similar?
It doesn't have to be for the PC0085 PLC, just any model or brand.

Did you see this thread?
http://www.plctalk.net/qanda/showthread.php?t=104998

jraef said:

Did you see this thread?
http://www.plctalk.net/qanda/showthread.php?t=104998

Click to expand...

Yes I have seen the thread and offered some suggestions to get the OP at least a working solution, which he has. This is just another approach to the same problem and I am trying to find a way using the audio recorded data. Thanks.

Boy.. Any idea what the waveform looks like? Did they use peaks and valleys for just ones and zeros?

(Reason being, I think you could do this in matlab, but it would be an interesting program to write)

Dravik said:

Boy.. Any idea what the waveform looks like? Did they use peaks and valleys for just ones and zeros?

(Reason being, I think you could do this in matlab, but it would be an interesting program to write)

Click to expand...

Man, would it ever! I wouldn't even know where to start but I bet it's not as simple as counting the 1's and 0's out of the waveforms. It might work the same as a modem? Telex? Even if you figured out the protocol you'd still have to translate the raw binary data into ladder logic and reverse engineering that sounds like a nightmare. I'd bet money it doesn't look like nice ASCII "XIC A OTE B" or whatever.

You guys are giving me flashbacks to my Atari 400 with cassette recorder. I would get home from school and watch Gilligan's Island and eat a PB&J while my latest creation loaded into the computer. I could tell if something went wrong with the file loading process by the sound of the recorded program coming through the TV in the other room. Sure, it took fifteen minutes to load a big file, but that little indestructible computer was "READY>" 2 seconds after applying power and would run for months without any freezes.

Binary FSK tone transmissions of data? That was an old way of sending data files via phone lines.

I'm just guessing and really have no clue. I appreciate all the suggestions.
I really don't know about the waveforms, it just sounds a lot like the sound an old dial-up modem makes when it is sending data. It looks like a fun project. I have tried playing it with Audacity software but I don't even know how to use it. I was hoping to learn something that way. Even if the file would convert to binary or hex that would be a start. Maybe I need something like an old acoustic coupler and modem.

When I was an apprentice, I saw something like this. My supervisor came into the office and told me that an old GE Fanuc PLC had lost it's memory. He rummaged around in the cupboard and pulled out a cassette. "Aha, the backup files!". He rummaged around some more and pulled out an old cassette deck. The deck had little white paint marks on the volume controls, indicating exactly where to set the volume to perform the backup and restore functions. "Aha, the programming device!". He rummaged around some more and pulled out a 3.5mm jack cable. "Aha, the communications cable!".

Even with my exposure to some fairly old and obsolete equipment to date, that still blew my apprentice mind. Unfortunately, the PLC's mind was blown even more, so by 11pm that night, it was in a skip and we had an S7-300 in it's place

I suspect that the easiest (and quite possible only) way of translating it would be to get hold of the PLC that uses that waveform as a backup medium, and restore it to the PLC. Then use software (if it's available) or a handheld programmer or the PLC's own faceplate to scroll through the ladder and document it all. But I'm interested to know how this one turns out - I mean surely there's some kind of design behind it all, but reverse engineering that pattern does not sound like the sort of thing I'd do for fun

ASF said:

Snip.....

I suspect that the easiest (and quite possible only) way of translating it would be to get hold of the PLC that uses that waveform as a backup medium, and restore it to the PLC. Then use software (if it's available) or a handheld programmer or the PLC's own faceplate to scroll through the ladder and document it all. But I'm interested to know how this one turns out - I mean surely there's some kind of design behind it all, but reverse engineering that pattern does not sound like the sort of thing I'd do for fun

Click to expand...

Using a HandHeld Programmer is exactly what has been done so far by the person I am trying to help. I have the ladder programming software and Dongle (very rare), but not a HandHeld Programmer to connect to a plc for reloading purposes. I suspect that I will need to get a HandHeld Programmer to reload a plc using the audio type data file and then connect with the Dongle and software to get it to Ladder. I was hoping to avoid purchasing a HandHeld Programmer but there may not be any other solution.
Again, I appreciate any and all suggestions. Thanks.

IMO it's not an easy task. Something like:

a) Filter the signal using a zero-crossing detector.
b) Recover the original binary stream and store it.
c) Identify a pattern in the stream (header, sync, data).
d) From the data, identify the opcode and translate it into ladder.

Having short applications in ladder and wav would be useful to generate a dictionary. But I know it's not possible.

So, the handheld is the best option.

Thanks to everyone for the suggestions. I have decided to buy a used HandHeld programmer as it seems to be the easiest option. I ordered one off ebay today.