i need to evaluate a safe method for connecting a PLC controller with an E-stop for dangerous machinery. Would this be suitable: 

For a safe PLC controller system, IEC 61508 specifies that in order to provide functional safety, the safety devices/control system should function correctly and in the event of a failure, the plant or machine must be brought into a safe shut-down state. For a safe PLC system, emergency stop buttons and safety guard switches are to be hardwired and therefore not dependant on the PLC software. This enables the system to be safe when there is a failure of the stop switch or PLC making it a fail-safe system. In order to provide a safe emergency, stop device for a PLC, this should be hardwired from the output into the motor for the dangerous machinery therefore not being dependant on the PLC program and not allowing the motor to restart when the button is released. The isolator for the system can include an auxiliary contact as the PLC input to enable the auxiliary on the contactor to be used to latch the starter. The e-stop and isolator are to be located outside of the PLC enclosure and must be easily accessible to the operator to enable them to be utilised quickly in case of an emergency. For a piece for dangerous machinery, this would be located visibly next to the operator workstation therefore able to be used quickly if required.

IN THE US:

You can use Dual Circuit Safety (DCS). Special safety rated relay's. ESTOP mushrooms that require a mechanical reset (and estop labeling)   to stop the CRUSHER from running. https://mall.industry.siemens.com/mall/en/WW/Catalog/Products/10143262#

OR Safety PLC. Which requires 2 CPU's to monitor Circuits for Safe operation. When circuit is open - check that DCS is not shorted. When closed, they come on together (within ms of each other). Order a safe PLC, and as many inputs as you need. and as many outputs as needed.  DO NOT USE NORMAL INPUTS OR OUTPUTS FOR SAFETY.

BOTH of these methods require dual circuit  wiring.  Actual requirements depend on two main factors. "Industry Standard Practice" is the legal phrase that matters.  Severity of the offending danger.  Frequency of the offending danger.   GOOGLE "Risk Assessment" . Some problems can be mitigated by a barrier. Depending on access requirements, some problems can use a light barrier.

The short answer is yes.