PMAC Product Guide Note: A motor that is currently running a motion program cannot be jogged with online commands. To jog the motor you must stop the motion program first with the A or Q online command. Axes and Coordinate Systems A coordinate system in PMAC is a grouping of one or more motors for the purpose of synchronizing movements. A coordinate system (even with only one motor) can run a motion program; a motor cannot. PMAC can have up to eight coordinate systems, addressed as &1 to &8, in a very flexible fashion (e.g.
eight coordinate systems of one motor each, one coordinate system of eight motors, four coordinate systems of two motors each, etc.) An axis is an element of a coordinate system. It is similar to a motor, but not the same thing. An axis is referred to by letter. There can be up to eight axes in a coordinate system, selected from X, Y, Z, A, B, C, U, V, and W. The simplest axis definition statement is something like #1->X . This simply assigns motor #1 to the X-axis of the currently addressed coordinate system. When an X axis move is executed in this coordinate system, motor #1 will make the move. The axis definition statement also defines the scaling of the axis’ user units.
For instance, #1->10000X also matches motor #1 to the X axis, but this statement sets 10,000 encoder counts to one X-axis user unit (e.g. inches or centimeters). Permitted Axis Names: X, Y, Z, U, V, W, A, B, C X, Y, Z: Traditionally Main Linear Axes • Matrix Axis Definition • Matrix Axis Transformation • Circular Interpolation • Cutter Radius Compensation A, B, C: Traditionally Rotary Axes (A rotates about X, B about Y, C about Z) • Position Rollover (Ix27) U, V, W:
Traditionally Secondary Linear Axes • Matrix Axis Definition Online Commands Many of the commands given to PMAC are on-line commands; that is, they are executed immediately by PMAC to cause some action, change some variable, or report some information back to the host. Some commands, such as P1=1 , are executed immediately if there is no open program buffer, but are stored in the buffer if one is open. Other commands, such as X1000 Y1000 , cannot be on-line commands; there must be an open buffer. These commands will be rejected by PMAC (reporting an ERR005 if I6 is set to 1 or 3) if there is no buffer open.
Still other commands, such as J+ , are on-line commands only and cannot be entered into a program buffer (unless in the form of CMD"J+" ). There are three basic classes of on-line commands: motor-specific commands, which affect only the motor that is currently addressed by the host; coordinate-system-specific commands, which affect only the coordinate system that is currently addressed by the host; and global commands, which affect the card regardless of any addressing modes. 44 Programming PMAC