[RBCMan]

I am a new operator of a Unisign machine (model # unknown), which uses the Siemens programming language. I have a problem cutting a CCW radius with left-hand cutter compensation active. The problem arises when the machine reads ahead and give me a "wrong block" error message for the CCW radius. This is what I've programmed:

G58 x15 y-3.375
G0 X0 Y0
Z.2
G1 Z-.8
G41 X0 Y2
X-3
G3 X-4 Y1 J-1 (this is the line that give the machine the error)

I'm having a hard time determining whether the J is the correct radius variable, or should I use the I for the radius? This has stumped me for a long time, and I really would like to know once and for all how to use the I and J.