Tormach PCNC 770 - Error Handling; Modality and Modal Commands; Modal Groups

Chapter 7
96
UM10350_PCNC770_Manual_0916A
Programming
Order of Execution
Order Item
15 Cutter radius compensation on/off (G40, G41, G42)
16 Tool table offset on/off (G43, G49)
17 Fixture table select (G54 – G58 and G59 P~)
19 Set path control mode (G61, G61.1, G64)
19 Set distance mode (G90, G91)
20 Set canned cycle return level mode (G98, G99)
21 Home, change coordinate system data (G10) or set offsets (G92, G94)
22 Perform motion (G00 to G03, G12, G13, G80 to G89 as modied by G53)
23 Stop (M00, M01, M02, M30, M60)
7.4.3 Error Handling
This secon describes error handling in PathPilot. This operang system somemes ignores things it
does not understand. If a command does not work as expected or does nothing, check it was typed
correctly. The operang system does not check for excessively high machining feeds or speeds. Nor does
it detect situaons where a legal command does something unfortunate, such as machining a xture.
7.4.4 Modality and Modal Commands
G-codes and M-codes are, generally speaking, modal. Modal commands cause the machining
system to change from one mode to another. The mode stays acve unl another command changes
it implicitly or explicitly. For example, if coolant is turned on (M07 or M08) it stays on unl it is
explicitly turned o in the program (M09). A few G-codes and M-codes are non-modal. These codes
have eect only on the lines on which they occur. For example, dwell (G04) is non-modal.
7.4.5 Modal Groups
Modal commands are arranged in sets called modal groups, and only one member of a modal group
may be in force at any given me. In general, a modal group contains commands for which it is
logically impossible for two members to be in eect at the same me – for example inch units (G20)
vs. millimeter units (G21). A machining system may be in many modes at the same me, with one
mode from each modal group being in eect.
Modal Groups for G-codes
Group 1 =
{G00, G01, G02, G03, G33, G38.x, G73, G76, G80, G81, G82, G84, G85, G86, G87, G88, G89}
motion
Group 2 = {G17, G18, G19, G17.1, G17.2, G17.3} plane selection
Group 3 = {G90, G91} distance mode
Group 4 = {G90.1, G91.1} arc IJK distance mode
(...continued)
(connued on next page...)