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