Synchronous analog output on multiple devices

[labview_novice_1]

My goal is to ultimately have syncronous analog and digital output using all channels (8 analog, 8 digital per dev) from three Devices (all 6733's) which are connected using a RTSI cable in PCI slots.  I want Dev 1 to be the master and Dev 2 and Dev 3 slaves.

From the example https://decibel.ni.com/content/docs/DOC-11706 which introduces synchronized Analog Output on multiple devices (RTSI)

I wrote the following vi (attached).  However I am getting an error at the slaves Start Task (-89137), specified route cannot be satisfied, because it requires resources that are currently in use by another route.  This error also appears when I run the original vi.

Any help would be much appreciated.

[Beutlich]

On your Master AO task, the export signal needs to be a route that is part of the device for that task. If you have Dev1 as your master, the export signal VI should export to Dev1/RTSI1. You currently have Dev2/RTSI1 on both tasks, so one of them needs to change, and I think you want the master AO to have Dev1/RTSI1. You will get error 89137 if you try to route through different boards in the same task because they are not directly connected (that's why there is a RTSI cable). 

The original VI should work as long as you have two devices, and only one device name is used for any particular task. The example has Dev3 and Dev5 defaulted. If you change Dev3 to Dev1, don't change any Dev3s to Dev2s, or you will get that error (error 89137 also will occur if you reference a device name that simply does not exist).