Direct access to PXIe trigger bus

[mgoldman5]

I am thinking about building an RF supply system around a Keysight M3202A AWG housed in a PXIe chassis.  The AWG has an option to use an integrated FPGA to perform realtime feedback, but the problem is that the AWG only accepts digital inputs (besides the trigger) through the backplane. 

Since I would like to pipe in as many digital signals as possible, is there any way to access the PXI trigger bus directly?  The timing and synchronization modules (PXI-6683, PXIe-6672, and PXIe-6674T) only give access to 3 or 6 trigger lines through PFI lines.  They also include onboard high-accuracy clocks that I do not need; in fact, I will select a chassis with an external clock input precisely because I need to sync it to our master experiment clock.  Something as simple as 8 SMB inputs on the front panel connected to the bare minimum of routing circuitry would be perfect, but it's not obvious that such a card exists.

Also, I'm assuming that, even though the trigger bus is designed to transmit short trigger pulses, the lines can also handle being driven high or low for long periods of time to serve as flags.  Please correct me if I'm wrong on this.

Thank you for your help!

[mgoldman5]

As a brief follow-up, we're also considering using two PXI-6541 cards to drive a switch network.  Since they have four PFI channels each, does anyone know if these PFI lines can be routed directly to the trigger bus instead of serving as trigger inputs for the HSDIO card itself?  That would get us access to the bus without the added expense of a synchronization card.