Preparing the OMNI VI for Remote Power Switching
The ability to turn the OMNI VI was a definite requirement for me. I cannot not conceive of leaving my OMNI on for a week or more at a time. Neither can I conceive of a catastrophic event (no matter how unlikely) occurring while operating from Europe and not being able to turn off the rig. If you are only going to operate from your office nearby, then you might not need this capability. The Interface Unit which you will build in the next step has the capability to switch the 13.6 power in the OMNI, but a little preparation is required.
Before proceeding, you are probably thinking "Why not leave the OMNI VI turned on and switch its power supply on and off?" If you try this, you will discover right away that this is not something you want to do. All of the memories will be corrupted and remote operation will not be possible. THE POWER SUPPLY MUST BE ON PRIOR TO SWITCHING ON THE OMNI VI and THE POWER SUPPLY MUST STAY ON UNTIL AFTER THE OMNI VI IS TURNED OFF.
The OMNI VI POWER switch is configured in such a way that switch electronically is very easy to accomplish. Unfortunately it is a bit difficult gain access to the point to connect our switching signal. Electrically, the same thing happens as when the power switch is turned on.
The drawing below shows the BS250 MOSFET and two 1000 Ohm resistors which are to be added at the DC Input Board. You will need to connect these three components inside the OMNI and bring out a wire which will be attached to a 3.5 mm mono plug. This plug will attach to the Interface Unit.
