years ago(1990)I needed a 20 ft cable to run my plotter,...I had to have one made up and all the techs told me it
The real problem with long cables of any port type (usb, parallel, serial) is the timing with the signal pulses and cable shielding and the impedance and signal reflection and baud rates.. The signals go in two directions. One signal may be going while the machines sends another back to the computer. If signal one is late getting back the computer will flip out and cause a error.
In the old days cables were limited to about 18 ft. (6 meters) for standard usages. That was the rule of thumb to cover any problems with the old rs232 interface.. And the old lesser quality cables. Also, laying two next to each other sometimes caused a problem because the signals would leak between the two.
However, our cutters usually run at about 9600 baud (slow). And the cables today are shielded very well. Therefor some machines might run with a cable up to about (10 meters) 30 ft or more. This is dependent on the cable shielding the drains and quality etc. Your mileage may vary.
Parallel cables,,,
The old Centronics parallel cables, (1980's) can rarely be more than 15 feet long and still operate correctly, and 9 to 12 feet is a safer limit. Yes, I made a few of those back in the day when you had to make your own.
But the newer IEEE-1284 can go up to 30 feet in length. I know that for a fact because I run a printer in another room on a 30Ft cable.