Axis Definition Registers

The Axis Definition registers contain axis assignment information. These registers are not intended to be accessed directly by the user. In general, do not read or write to these registers. To define the axes on the RMC, use RMCTools. For details, see the Defining Axes topic.

In rare, advanced cases, the user may wish to change the axis definitions as part of the machine operation. This topic describes these registers and how to write to these registers from a host controller to change the axis definitions. Notice that changing axis definitions requires restarting the RMC, and therefore cannot de done while motion is in progress.

The Registers

The axis definition registers contain two areas: the Current Axis Definitions and the Requested Axis Definitions.

The Current Axis Definitions and the Requested Axis Definitions will generally be the same except in two cases:

(1) The user has written to the requested block and intends to do a warm restart or burn to flash and do a cold restart, or

(2) The requested axis definitions found on startup are invalid for the current hardware configuration; in this case the Current Axis Definitions will be the default for the current hardware configuration.

Changing the Axis Definitions from a Host Controller

Delta recommends changing axis definitions only in RMCTools. However, if your application absolutely requires it, you can change the axis definitions from your host controller (such as a PLC) by writing to the axis definition registers. This section describes how to do so.

The axis definition registers are fairly complex. Therefore, Delta recommends that you do not try to figure them out and write to the ones you need. Instead, Delta recommends that you use RMCTools to define the axes as you desire, then read all of the Current Axis Definition registers and save the data. Then, to apply that axis definition later, write that data to the Requested Axis Definition registers, update Flash, and restart the controller. The procedure is given below:

1. Obtain the Axis Definitions
   For each set of axis definitions that you will need, do the following:

   1. In RMCTools, set up the axis definitions as you desire, and apply them to the RMC.

   2. With your host controller, read the Current Axis Definitions registers, and store that data for later.

2. Apply the Axis Definitions
   Each time you wish to change the axis definitions, write your stored Axis Definitions to the Requested Axis Definitions registers.

3. Restart the RMC
   The RMC75, RMC150, and RMC200 can be restarted by writing to the Loader Command register. The following methods are available. See the Loader Command topic for details.

   1. Cold Restart with Flash Update
      This method first updates Flash, then does a cold restart of the RMC, which is the same as cycling power. Use this method if you want to automatically save the Axis Definitions to Flash and then restart.

   2. Cold Restart without Flash Update
      Does a cold restart of the RMC, which is the same as cycling power. You must manually save anything to Flash before using this method.

   3. Warm Restart
      This method does a warm restart, which retains all the data in the RMC, but doesn't save to Flash. Notice that the restart will apply the new axis definitions and will set all variables to initial values.

4. Restart Communications
   If communicating over USB or serial, wait 4 seconds for the controller to be ready to communicate again. If communicating over Ethernet, wait 8 seconds. After waiting the specified time, re-open the connection to the controller and resume communication.

5. If you changed axis definitions, some parameters may have changed and you may need to update them.

Axis Definition Registers Details

In each axis definition area (current and requested), there are four 32-bit DWORD registers per axis. Here is how these registers are defined:

n = axis number

See Also

Loader Command

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