Motion Hold is a feature available to any motion on an Axis or MultiAxis. The feature allows the user to command (and therefore load) a motion that should not execute immediately. The motion will be triggered by some real-time condition monitored by the RMP firmware.
There are three main types of Motion Hold:
- I/O triggered motion - A motion holds its execution until an I/O value reaches the desired state.
- Position triggered motion - A motion holds its execution until an Axis position is exceeded.
- Software triggered motion - A motion holds its execution until a bit is set in the RMP’s firmware memory.
Motion Hold is especially useful when a motion needs to have a very tight synchronization with some other process -- when the synchronization must be accurate to less than one millisecond. A Windows app cannot offer this level of synchronization so it must be configured into the RMP for processing in the real-time firmware for sub-millisecond response to start motion.
Some examples of when Motion Hold might be used for various types: