Fault Input for any RMC150E position axis

The RMC150E has a physical discrete Fault Input only on the Quad module. To implement fault input functionality for position control axes that use RMC150 modules other than the Quad, follow the instructions below.

  1. Choose any general-purpose discrete input on the RMC to use for the fault input functionality. This can be on the DI/O, UI/O, or CPU modules.
  2. In the project pane, expand the Programming folder and double-click Discrete I/O. Use this Discrete I/O editor to find the address of your chosen discrete input.
  3. In the Axis Parameters, on the All tab, in the Feeback section, set the Positive Limit Input and Negative Limit Input parameters to use your chosen input. They are listed by address.
  4. In the Axis Parameters, on the Setup tab, in the Halts section, set the Autostops for the Positive Limit Input and Negative Limit Input to the desired level of halt, which is typically Open Loop or Direct Output, but this depends on your application.
  5. The Limit Input Polarity parameter will now be visible. Set it to the desired polarity. Typically, this will be Active Low, for fail-safe functionality in the case of wiring breakage.
  6. Make sure to download your changes and update Flash.

Now, when the discrete input turns on, the axis will halt according to the Autostop. If a motion command is sent to the axis while the input is on, the axis will halt and not move. Notice, however, that the Direct Output command can always make the axis move in open loop, regardless of any error bits that are on. This is usually not a problem, because the Direct Output command should only be used during setup or troubleshooting, and not during normal machine operation.

To halt other axes with this same input, simply set up the Positive Limit Input and Negative Limit Input parameters to use that same input.