ETC Ion DMX input query

As Ueli commented, the Eos family desks do not support a DMX input function, so any DMX going into the 4 port Gateway is not going to the desk to be acted upon.

That said, it sounds like all you need is the ability to use the house desk as the functioning console until such time as a show console is up and running.  As well, you can as needed have both the house Ion as well as the visiting console operational at the same time.  

So question one becomes - is this a networked system ? and is the Ion connected via a Cat5 cable ?.  If so you can connect the gateway to the network at either another Cat5 connection point, or into a switch near the Ion, then simply plug the visiting console DMX into port 4 as you have it set up, if and when the visiting desk is up and functional.  Both desks will be sending DMX to the system in a highest takes precedence mode, so maybe power down the Ion prior to show.  

If the system is not a network, you can re-configure the gateway for 2 DMX universe 1 inputs (assuming you are only controlling one universe), then have both desks input to the gateway at the same time.  Note though that the typical configuration for Net3 gateways when using as a DMX merger (which is essentially what it's doing) is that a lower numbered port has priority over a higher number port.  Thus any DMX at a value of zero inputting to port one would over-ride the inputs to higher numbered ports.  You might want to check this in the gateway manual as you might be able to change this configuration.  Or just swap DMX from the Ion to the visiting at half hour or so.  

FWIW, I often keep my Ion up and running with a visiting console in use.  I have a networked system so it's an HTP setup.  I sometimes have the channel to address patch for the event in the Ion to make it easier on the LD, but if not given that info. I will do a one to one patch so as to have the channel and address the same.  This eliminates the slight lag the console exhibits when calling up addresses not patched to channels.  

As Ueli commented, the Eos family desks do not support a DMX input function, so any DMX going into the 4 port Gateway is not going to the desk to be acted upon.

That said, it sounds like all you need is the ability to use the house desk as the functioning console until such time as a show console is up and running.  As well, you can as needed have both the house Ion as well as the visiting console operational at the same time.  

So question one becomes - is this a networked system ? and is the Ion connected via a Cat5 cable ?.  If so you can connect the gateway to the network at either another Cat5 connection point, or into a switch near the Ion, then simply plug the visiting console DMX into port 4 as you have it set up, if and when the visiting desk is up and functional.  Both desks will be sending DMX to the system in a highest takes precedence mode, so maybe power down the Ion prior to show.  

If the system is not a network, you can re-configure the gateway for 2 DMX universe 1 inputs (assuming you are only controlling one universe), then have both desks input to the gateway at the same time.  Note though that the typical configuration for Net3 gateways when using as a DMX merger (which is essentially what it's doing) is that a lower numbered port has priority over a higher number port.  Thus any DMX at a value of zero inputting to port one would over-ride the inputs to higher numbered ports.  You might want to check this in the gateway manual as you might be able to change this configuration.  Or just swap DMX from the Ion to the visiting at half hour or so.  

FWIW, I often keep my Ion up and running with a visiting console in use.  I have a networked system so it's an HTP setup.  I sometimes have the channel to address patch for the event in the Ion to make it easier on the LD, but if not given that info. I will do a one to one patch so as to have the channel and address the same.  This eliminates the slight lag the console exhibits when calling up addresses not patched to channels.