The manual states:

10.7.22.4  G83  and G83.1 Cycles 
The G83 cycle (often called peck drilling) and G83.1 (rapid peck drilling) is intended for
deep drilling or milling with chip breaking. See also G73. The retracts in this cycle clear the
hole of chips and cut off any long stringers (which are common when drilling in aluminum).
This cycle takes a Q number which distance used by each peck. Program 
  G83 X~ Z~ R~ L~ Q~ 
Preliminary motion, as described above. 
Move the Z-axis only at the current feed rate downward by delta or to the Z position,
whichever is less deep. 
For G83 rapid back out to the clear Z. For G83.1 rapid out by the peck distance (Q)
Rapid back down to the current hole bottom, backed off a bit. 
Repeat steps 1, 2, and 3 until the Z position is reached at step 1. 
Retract the Z-axis at traverse rate to clear Z. 
It is an error if: 
·  the Q number is negative or zero.

L - number of repetitions in canned cycles/subroutines key used with G10

However I can't see what "L" is for? I have tried it and it seems to do nothing (tried several different numbers).

Is it relevant?

thanks
Rimmel

Here is a broader description, also in the Summary of G-codes from the Mach3 screen.
Russ

Thanks for the info - I sort of gathered that but when I add L5 in absolute mode the operation does not repeat 5 times. I completes once and stops.

thanks again
Rim

Try this .......

G0 G49 G40  G17 G80 G50 G90
G20 (Inch)
G90
G83 X2 Y2 Z-0.50 Q0.20 R0.10 F5.00 L5
G80
M30

........ works well here.
Russ

Thanks - will do.

Quick couple of question though:-

1) Why G90 after G20 when you already have G90 in the top line?

2) Again why G80 after G83?

thanks again
Rim

The firs line is a basic initialization fo any following code.
This was generated by the wizard.

G80 cancels the Canned cycle.

You could have the following  where it goes to multiple positions and keeps running the peck cycle .... you have to cancel that at the end.

G0 G49 G40  G17 G80 G50 G90
G20 (Inch)
G90
G83 X2 Y2 Z-0.50 Q0.20 R0.10 F5.00 L5
x3
x4
x5
x6
(and so on)
G80
M30

Also see that to do a L repeat on the subsequent locations, youd need an L# at each one.
ie:
X3L5
X4L5
and so on.
 Don't know why you'd use it, but there it is.
Russ

Thank you very much.

Rim