Polar Interpolation Problem

[jason03]

We have a recently bought a Massa VL1200 atc+c with 18i-TB controll and trying to program C-Axis but i think there may be a problem with Parameter setup.

e.g. program a square 600mm
G00 X650. C0
Z-10.
G112
G41 G01 X600. C0.
X600. C-300.
X-600. C-300.
X-600. C300.
X600. C300.
X600. C0.
G40 X650.
G113
This code works fine but if we want to start cutter at C90. we would have to program points exactly as above after moving to G00 X650. C90., C-Axis seems to be auto setting rapid move before G112 to new C0.
I would expect program to be as below
G00 X650. C90
Z-10.
G112
G41 G01 X0. C300.
X600. C300.
X600. C-300.
X-600. C-300.
X-600. C300.
X0. C300.
G40 X325.
G113

Please help
Any info appreciated

[dcoupar]

From the manual:

The virtual axis is at coordinate 0 immediately after G12.1 is specified.
Polar interpolation is started assuming the angle of 0 for the position of the tool when G12.1 is specified.

So, when you activate G12.1 (G112), whatever position C-axis is currently at becomes 0.