Issue uploading files to Fanuc CNC machines

[JacquesK]

Hello,

I consult to an engineering company that have multiple Mazak and Fanuc CNC machines but have a VERY outdated IT infrastructure. Current PC is a 386 running MS-DOS 6.1 and/or Windows 3.1. Software currently used to load the machine files is NCNet Lite v0.x as well as an old version of WinComms.

We are in the process of upgrading the PCs and laptops we use to load machine files on our Fanuc machines (Series O-M and Series 18-T). We are also evaluating various DNC software applications and have chosen 'DNC Precision' (www.dnc-precision.com) and we are currently trialling this.

We have managed to establish comms between the PC/laptop and the various Fanuc machines (using customised settings). These settings are:
4800, 7, EVEN, 1, polling and no software handshake.

The problem that we are experiencing is as follows:

1. The file number is entered on the Fanuc and 'Input' button pressed
2. 'LSK' flashes on Fanuc monitor
3. We transmit the file from the PC/laptop, it shows 612 bytes transmitted and then pauses.
4. The flashing 'LSK' disappears on the Fanuc monitor
5. 'Reset' button is pressed
6. The file name is entered and 'Input' button pressed
7. 'Input' flashes on the Fanuc monitor
8. The application on the PC/laptop then transmits the rest of the file successfully.
8. The contents of the uploaded file is then shown on the Fanuc monitor.

It seems that the application on the PC/laptop is waiting for some sort of signal from the Fanuc machine before continuing the upload of the file. This signal is obviously generated in steps 5-7 above.

I need to solve the problem of the PC/laptop waiting for the signal from the Fanuc but I have no idea where to start.

Does anybody have experience with this and can help me out?

Much appreciated!

[Al_The_Man]

It has always been my understanding that Fanuc uses XON/XOFF (s/w H.S.)
I have always used a 3 wire cable, with hardware handshake jumpered out at both ends.
Al.

[dcoupar]

Software handshaking should be on. I just installed a 24 machine Predator DNC system with various Fanuc 0, 6, 10, 11, 18, and 21 controls. They were all set to use software (XON/XOFF) handshaking, and all worked right from the get-go.

[Dan Fritz]

Your DNC software is probably sending a Line-Feed (LF) as a "leader" before the percent sign at the beginning of your file. Here's what I think is happening:

The Fanuc (all Fanucs) use the "LSK", or Label Skip function to ignore all data prior to the first LF that comes in. This was used in the olden days of reading paper tapes by letting the control ignore all the man-readable "label" on the leader of the tape. Any junk, jibberish, null characters from a blank leader, etc. are ignored until that first LF comes in. After that, the Fanuc reads data until the NEXT percent sign comes in.

In your case, I'm guessing that the control is getting a Line-Feed, which cancels LSK, then the control starts reading. Unfortunately, the first thing it gets from the DNC system is the percent sign at the top of your file, which STOPS the Fanuc from reading further. The Fanuc sends an Xoff, stopping the DNC system with some data in the output buffer (your 612 bytes or so). The SECOND time that you press READ on the Fanuc, the control reads the file properly because the DNC system has already sent the percent sign and now can send the program.

If this is what's happening, then the solution is to do this (we do this in our PC-DNC Plus software):

1) Have the DNC system send a "Leader" which contains only a LF character. A leader is what the DNC software sends before sending the data in your file.

2) Have the DNC software send a percent sign as a "Trailer" after your file is sent

3) Have your DNC software "mask out" or ignore any percent signs that are IN your file.

These three steps will guarantee that all file transmissions begin with a LF, end with a percent sign, and that no "double" percent signs will be sent. Note that this will be true whether or not your files have percent signs in them. We have customers with a library of thousands of files, half of which have percent signs and the other half without. This prevents you from having to edit those files.

You must have a LF prior to the first block of the program, otherwise the Fanuc won't read the first block (with your O-number). If the file has an O-number in it (and there is a LF before it), there is no need to manually enter that O-number. The Fanuc should see it and use it automatically. The only time you should have to manually enter the O-number is if you want to load a file into the control and save it using a DIFFERENT O-number.

Hope this helps.