NAME

       estop_latch - Software ESTOP latch

SYNOPSIS

       loadrt estop_latch [count=N|names=name1[,name2...]]

DESCRIPTION

       This component can be used as a part of a simple software ESTOP chain.

       It has two states: "OK" and "Faulted".

       The  initial  state is "Faulted".  When faulted, the out-ok output is false, the fault-out
       output is true, and the watchdog output is unchanging.

       The state changes from "Faulted" to "OK" when all these conditions are true:

              •      fault-in is false

              •      ok-in is true

              •      reset changes from false to true

       When "OK", the out-ok output is true, the fault-out output  is  false,  and  the  watchdog
       output is toggling.

       The state changes from "OK" to "Faulted" when any of the following are true:

              •      fault-in is true

              •      ok-in is false

       To  facilitate  using  only  a single fault source, ok-in and fault-en are both set to the
       non-fault-causing value when no signal is connected.  For estop-latch to ever be  able  to
       signal a fault, at least one of these inputs must be connected.

       Typically,  an  external  fault or estop input is connected to fault-in, iocontrol.0.user-
       request-enable is connected to reset, and ok-out is connected  to  iocontrol.0.emc-enable-
       in.

       In  more  complex  systems,  it may be more appropriate to use classicladder to manage the
       software portion of the estop chain.

FUNCTIONS

       estop-latch.N

PINS

       estop-latch.N.ok-in bit in (default: true)
       estop-latch.N.fault-in bit in (default: false)
       estop-latch.N.reset bit in
       estop-latch.N.ok-out bit out (default: false)
       estop-latch.N.fault-out bit out (default: true)
       estop-latch.N.watchdog bit out

AUTHOR

       John Kasunich

LICENSE

       GPL