Unfortunately the proposed method does not work in conjunction with impositioning. Believe the only way to achieve this is by doing a second pass (admittedly I’m not a print output expert, so others may correct me… and please do ;).
Step 1, impositioned output
Create impositioned (but no seperations) output for your document. There is no need to add a slipsheet section as proposed in previews replies (and no need for a Control Script). Set the Stack Depth in the Imposition settings of the Print Wizard to the number of sheets for each stack. We use this information to insert a slipsheet in the steps below. Generate your impositioned output (in my case simplex pages in PDF format).
Step 2, map impositioned output
Create a new DataMapper based on the impositioned output (File > New Data Mapping Configuration > Files > PDF). Browse for the file and click Next. A new DM config appears.
Locate the Settings pane and set the ‘Number of pages’ for the On Page boundaries to the stack depth defined in step 1. When generating duplex output you will need to double the value. This creates a new data set where each record contains PDF images for the pages in the stack.
Step 3, create template for second pass
Create a new print template using the page size of the impositioned sheet. Set the Background Image of Section to the PDF DataMapper input.
This automatically generates pages in your section, one page for each sheet side in your data record (in other words; the number of pages you defined in the On Page boundaries).
Step 4, add slipsheet section
Add a new section to the print template, this will be your slipsheet. There is no need to create a Control Script. Place the section before or after Section 1 depending on where you want the slipsheet to appear.
In my case I added an absolute position box and added some dummy info like the stack index and a timestamp. Generate output using separations and set the output split level to 1 document (e.g. per stack).
I ran some local tests and it seemed to do the trick. Attached my test files. I used a simple counter as my data (File > Add Data > Generate Counters), the Stack Depth was set to 10 and the output is simplex.
Hope this is of some help.
output-with-slipsheet.pdf (82.9 KB) slipsheet.pdf (70.5 KB)
slipsheet-2nd-pass.OL-template (8.4 KB)slipsheet-2nd-pass.OL-datamapper (20.2 KB)