Example 2 - Full 6X Machine

Now consider a similar machine, but this time the head can freely rotate around the X axis. This machine has 3 rotary axes, two on the table (X and Z) and one on the head (X).

GPP2 cannot control 3 rotary axes simultaneously. The user has to select which axes are active at any given time, and configure the machine accordingly. For the machine described here, either the head or the table X axes are stationary, probably at angle zero.

When the head axis is locked in place, this machine behaves as a Table-table (X-Z) machine. However, when the table X axis is locked, the machine behaves like a Table-Head machine (Z-X). It means that different arguments must be given to the DEFINE_MACHINE statement in each case. Clearly, it also requires different connection scenarios.

The role of the major angle variable changes. In the Table-Table configuration, A_CURPOS and A_LASTPOS refer to the table X axis. In the Table-Head configuration, they refer to the table Z axis. Similar dramatic changes take place regarding B_CURPOS and B_LASTPOS.

Therefore, whenever the configuration is changed, the EX2 program has to modify these variables according to the new configuration.