Lets Talk E-Stops

[JesperMP]

Back to the original topic.

I am designing a control system for a planar mill with nine RIO control stations.
[..] I have only worked with E-Stops that shut off everything controlled by the PLC complete.
[..] Is thier an industry standard for E-Stops for RIO?
[..] This would be only the fifth thing I've programmed ;

There are a quite a few warning signs here.
Is that "RIO" as in "Remote IO network" ?
Are you planning to solve the safety issues by programming ?
Unless we are talking about "safety PLCs" or "programmable safety relays" then you are on a wrong track.
Safety standards do not allow you to let a 'regular' PLC handle the E-STOP.

Exception: An electronic logic (hardware or software) system as well as the communication network or link that complies with both 9.4.3 and 11.3.4 and is listed for Category 0 emergency stop function shall be permitted.

This probably means a certified safety PLC or programmable relay.

Other think that the E-stops should shut off everything controlled within view of the operator; so that if another operator gets caught in a machine within view of someone else the other person can push thier own E-Stop and save them.

This is probably an excellent idea.
There are advanced programmable safety relays (and safety PLCs), that enable you to make overlapping safety zones.
But it is far from trivial, and probably not what you were thinking of.