Topic: Fadal 4020 vmc

By: Guest

Posted on: Nov 20 2010 at 04:44:44 AM

I have a fadal 4020 vmc, as of yet I have not been successful getting any of the null modem USB/rs232 cables to work and fadal before they closed their doors maintained at best that they were glitchy. Having a native rs 232 is the only bullet proof way to dnc to this machine. The machine came new with only 8k memory installed and they intended to dnc for production. there are tens of thousands of these machines out there being used by both production facilities and hobbyists. The choices yours

By: Administrator

Posted on: Nov 20 2020 at 04:46:46 AM

The above post was originally posted into the wrong thread.

Admin moved it to its own thread here.

By: Guest

Posted on: Nov 20 2020 at 05:10:05 AM

Note sure what you mean by "The Choices Yours"

As far as I know all versions of easyDNC and Remo can communicate with Fadal VMC.

Let us know what errors you get when trying to send to your Fadal.

If you're getting buffer overflows in the CNC then try the following.

1. Does the CNC support hardware flow control (Full Handshaking)? If it does then make up a cable with full handshaking. (I'll add wiring diagrams later) and set the DNC to use RTS/CTS/Hardware flow control.

2. Disable all FIFO. Go into Windows Device Manager. Select the COM port. Don't bother trying to do anything with baud rate and flow control. Just go to 'Advanced' and make sure FIFO sliders are set down to zero and any checkboxes as unchecked/disabled. SOme USB devices will just ignore this anyway but it's always worth a try.

3. increasing the 'Block delay' in the DNC software. This inserts a small gap between lines of data being sent to the CNC. Time for the old machine to catch its breath before the next block arrives. Maybe set Block Delay to the highest possible number and if that avoids overflows then reduce it a step or two.

4. Try a lower baud rate. Obviously if lowering the baud rate in the CNC then both CNC and DNC need to be set the same.

It might be worth trying the older EasyDNC version 4.7 The new EasyDNC/Remo v5 can run in true 64bit mode making use of multi processors. The old EasyDNC 4.7 is getting a little old now. Only runs one processor and can't work in 64bit mode. Might not make a difference but it's worth trying.

By: Guest

Posted on: Nov 20 2020 at 05:24:11 AM

3 wire null modem cable for software flow control. DC1/DC3 (also known as xOn/xOff)

Full hardware flow control. RTS/CTS

Not sure about Fadal but many machines do have a parameter to make the CNC use hardware flow control but then, for some reason, some machines such as Fanuc will then use hardware flow control when loading a program into CNC memory but then ignore hardware and use only DC codes when drip feeding. That's why most people create simple 3 wire cables.

If possible, if the machine is capable of it, hardware flow control is better.

Note in both cables there's that short link between pins 6,8 and 20 at the CNC end of the cable. That is important. If you buy a standard RS232 cable from a computer shop then it most likely won't have that 6.8.20 link and the CNC will often throw DR or DTR/DC errors etc. So. Make up your own cables and be sure to include that 6,8,20 link at the CNC end of the cable.

Topic: Fadal 4020 vmc

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