I'm getting an odd set of symptoms from a BoB I've got set up in a bench rig.  

Using a very basic macro that activates an output until an input signal is seen at one of the input pins, I am getting strange results. When the output is activated and the pin measured with a voltmeter, there is a steady 5v and the diagnostic LED flashes evenly. However, when a  5v relay is attached to the pin, the LED flashes erratically and the relay becomes unstable, toggling on and off.

From ports and pins, if the "Active low" option is checked or unchecked, the relay switches in accordance without problem. It is only when ActivateSignal is used on the switch side of the relay that the problem occurs.

I also have a brain setup that activates another output whenever an axis is moved. This scenario works fine with the relay, toggling it on and off in stable fashion as the DRO is altered.

I have tried the setup with two BOB's and the problem is the same. The two BOB's are similar but not the same.

I'm using Win 7.

I'd be grateful for any help - Cheers.