Print/Staple on HP Color LaserJet Flow 6800 with Finisher via PJL Doesn't Work

[RexSchrader]

We just acquired a HP Color LaserJet Flow 6800 with the 6800 finisher attachment.

I need to print 2 PDF documents, one from one tray (plain paper), one from another tray (labels), then staple the resulting bundle together.

I have written some PJL which ALMOST works, except that the first job outputs to the top tray (on top of the unit) and the second job outputs from the correct finisher tray. It does not staple.

Here is my PJL with PDF data omitted:

%-12345X@PJL
@PJL JOB NAME = "My Test Job"'
@PJL SET PROCESSINGACTION = APPEND
@PJL SET PROCESSINGTYPE = "STAPLING"
@PJL SET PROCESSINGOPTION = "ONE_STAPLE"
@PJL SET PROCESSINGBOUNDARY = MOPY
@PJL SET PROCESSINGTYPE="PUNCH"
@PJL SET PROCESSINGOPTION="NONE"
@PJL SET PROCESSINGBOUNDARY=MOPY
@PJL SET MEDIASOURCE = TRAY2
@PJL SET OUTBIN = OPTIONALOUTBIN3
@PJL ENTER LANGUAGE=PDF
--- PDF 1 DATA HERE ---
%-12345X@PJL
@PJL SET MEDIASOURCE = TRAY3
@PJL ENTER LANGUAGE=PDF
--- PDF 2 DATA HERE ---
%-12345X@PJL
@PJL EOJ
%-12345X

There are ESC codes in the right places.

The thing that is killing me, aside from it not stapling, is that the first document is coming out the the top tray and the second is coming out of the correct "OPTIONALOUTBIN3". This is the bottom output on the finisher. As per the installer, if I want to staple the documents they need to come out from that bottom bin on finisher because that's where the staples are.

I opened a ticket with support but they just sent me a generic PJL doc:
https://h10032.www1.hp.com/ctg/Manual/bpl13208.pdf

I did find this doc:  
https://h10032.www1.hp.com/ctg/Manual/c04549006.pdf

But it is for the M8xx Finishers, not the 6800 finisher. That's where I got the PROCESSING* commands above.

Please advise what I am doing wrong here or give me a link to the 6800 finisher specific PJL codes. I can't find any more detailed documentation for this specific printer/finisher combination. 

[Repairatrooper]

I have been asking HP for years to provide that type of functionality in the UPD driver sets so you could combine several documents and staple them together. I can think of a few reasons that it is not offered, including the fact that designers are worried about overloading the stapler by combining 2 jobs that exceed the physical limitations of the staple mechanism. They may see little to no demand for this feature, in part because software exists to merge PDF documents.Is this the internal or external finisher?

[RexSchrader]

To be clear: I am able to combine two documents into one job, at least as near as I can tell. Prior to making this purchase I had found someone who reported being able to do exactly what I'm trying, but I'm getting inconsistent results.

The thing that kills me is that there is just no reference material available for me to validate that my process is correct.

[RexSchrader]

I just realized that you had asked if it was an internal or external finisher. It's the external 6800 finisher which attaches to the side of the unit. It has the stapler on the bottom internal to the finisher. 

I have two separate by related issues:

1. Despite setting the output bin, only the second document in the job comes out of the finisher. The first comes out of the top. 

2. Nothing is being stapled

I don't know they proper PJL commands to tell it how to staple, and I can't find any PJL docs specific to my finisher online.