Hello,
when I create a PLT or a HPGL file I just get a single color draw.
I'm not able to find how to configure different pens for a multicolor plotter.
Can anyone help me?

Thanks,
Carlo

Maybe you have seen this?
https://www.timewasters-place.com/inksc ... s-the-3rd/

Maybe this:

• Release notes Inkscape 0.92 > Extensions > Plotter Driver > Multiple Pens
  (also described in 'Extensions > Export > Plot > Plotter Settings'; as well as in the dialog when saving as HPGL file in Inkscape 0.92)

It seems like it's been recently realized there's a problem opening and saving PLT files, in 0.92

For what it's worth: https://bugs.launchpad.net/inkscape/+bug/1658260

brynn wrote:It seems like it's been recently realized there's a problem opening and saving PLT files, in 0.92

For what it's worth: https://bugs.launchpad.net/inkscape/+bug/1658260

JFTR - Opening/Saving as HPGL (and 'Extensions > Export > Plot') does not use UniConvertor, and is not affected by that bug.

Thanks to everybody,
I've tried to use the "Multiple pens" solution, but I get a Debug information window (With a text in Italian - I'm not able to run the software in english)
I've tried to save as HPGL, but I still get a single color output.

Is there something I'm missing?
Thanks,
Carlo

I wouldn't mind to translate the Italian text, if you can paste it here.

The pop-up window says:
Inkscape ha ricevuto dei dati aggiuntivi dallo script invocato. Lo script non ha riportato errori, ma questo potrebbe indicare che il risultato non è quello atteso.

---------------------------------
Debug information
---------------------------------

Settings:

Serial Port: COM2
Serial baud rate: 9600
Serial byte size: eight Bits
Serial stop bits: one Bits
Serial parity: none
Serial Flow control: xonxoff
Command language: HPGL
Resolution X (dpi): 1016.0
Resolution Y (dpi): 1016.0
Pen number: 4
Pen force (g): 0
Pen speed (cm/s): 0
Rotation (Clockwise): 0
Mirror X axis: False
Mirror Y axis: False
Center zero point: False
Overcut (mm): 1.0
Tool offset (mm): 0.25
Use precut: True
Curve flatness: 1.20000004768
Auto align: True
Show debug information: True

Document properties:

Inkscape version: 0.92.0 r15299
Filename: disegno.svg
Document unit: mm
Width: 210.0 mm
Height: 297.0 mm
Viewbox Width: 210.0 mm
Viewbox Height: 297.0 mm

HPGL properties:

Drawing width: 118.049999998 mm
Drawing height: 83.3999999983 mm
Drawing width: 4722 plotter steps
Drawing height: 3336 plotter steps
Offset X: 10.0000000002 plotter steps
Offset Y: 10.0000000002 plotter steps
Overcut: 40.0000000008 plotter steps
Tool offset: 10.0000000002 plotter steps
Flatness: 1.20000004768 plotter steps
Tool offset flatness: 0.540000021447 plotter steps

HPGL data:

IN;SP4;PU0,0;PD0,90;PU2675,423;PD2670,422,2667,418,2666,416,1688,672,1688,667,1690,663,925,3,922,8,923,13,926,18,931,20,932,20,874,1029,869,1027,866,1024,2,1548,5,1552,11,1553,16,1551,19,1547,961,1914,958,1918,954,1920,1186,2903,1190,2901,1193,2896,1193,2891,1190,2886,1830,2104,1833,2108,1833,2112,2840,2196,2839,2191,2836,2187,2831,2185,2826,2187,2825,2187,2279,1337,2284,1335,2288,1336,2679,404,2674,403,2669,405,2666,410,2666,415,2666,416,2627,426;PU4722,1897;PD4722,1892,4725,1887,4729,1885,4731,1885,4728,1810,4719,1736,4718,1737,4704,1664,4684,1593,4659,1523,4629,1454,4628,1454,4594,1387,4593,1387,4554,1321,4554,1322,4510,1257,4509,1258,4461,1195,4460,1195,4408,1135,4407,1135,4350,1076,4289,1020,4288,1020,4223,965,4154,913,4081,863,4005,815,3925,770,3842,727,3756,687,3667,650,3575,615,3480,583,3480,584,3383,555,3283,529,3181,506,3181,507,3077,487,3077,488,2971,471,2971,472,2863,459,2753,450,2642,445,2529,443,2529,444,2421,445,2421,446,2313,451,2206,460,2100,473,1995,489,1892,508,1790,531,1691,556,1691,557,1593,585,1593,586,1497,618,1498,618,1404,653,1314,691,1226,732,1226,733,1141,777,1059,824,981,874,906,926,906,927,836,981,770,1038,708,1096,708,1097,651,1157,652,1157,599,1219,551,1283,552,1283,508,1348,509,1348,470,1414,471,1414,437,1482,438,1482,409,1550,410,1550,386,1620,387,1620,368,1690,369,1690,356,1761,357,1761,349,1833,347,1905,350,1977,351,1977,359,2048,360,2048,373,2119,374,2119,392,2189,393,2189,416,2258,417,2258,446,2326,480,2393,519,2459,563,2523,611,2586,612,2586,664,2648,665,2647,722,2707,723,2707,784,2765,785,2765,851,2821,922,2875,997,2927,998,2926,1076,2976,1077,2976,1159,3022,1244,3066,1332,3107,1332,3106,1423,3144,1516,3179,1516,3178,1612,3210,1710,3239,1710,3238,1810,3264,1810,3263,1911,3286,1912,3285,2015,3304,2119,3320,2120,3319,2225,3331,2333,3340,2441,3345,2549,3346,2662,3344,2773,3338,2883,3329,2883,3328,2991,3316,2991,3315,3097,3299,3201,3279,3303,3256,3402,3230,3402,3229,3499,3200,3594,3168,3685,3133,3685,3132,3774,3094,3860,3054,3860,3053,3943,3010,3942,3010,4022,2964,4098,2916,4098,2915,4170,2865,4239,2812,4304,2757,4303,2756,4364,2700,4364,2699,4421,2640,4473,2579,4521,2516,4565,2452,4564,2451,4604,2385,4603,2385,4638,2318,4637,2317,4666,2248,4690,2178,4709,2106,4708,2106,4722,2033,4721,2033,4730,1960,4729,1960,4732,1885,4731,1885,4730,1845;SP0;PU0,0;IN;

Mhm, it basically only says that it's going to print the debug info... To me, the numeric part at the end really doesn't look like it would be using more than one pen for the actual drawing, but 4 pens are selected (but I know exactly nothing about the file format, this is just a guess).

Did you follow the instructions in the release notes exaclty? (with layer names and all?)
Can you post the svg file?