Actually you are right: one can setup the userpage numbers by just saying way=byblock (no need to repeat numberconversionset).
Here is a complete example:

\defineconversionset[frontpart:pagenumber][][romannumerals]
\defineconversionset[bodypart:pagenumber] [][numbers]
\defineconversionset[backpart:pagenumber] [][characters]
\setupuserpagenumber[way=byblock]

\starttext

\startfrontmatter
\placecontent
\stopfrontmatter

\startbodymatter
\chapter{First chapter}
\input ward.tex
\section{A section}
\input dawkins.tex

\stopbodymatter

\startbackmatter
\chapter[title={Index},number=no]
\input tufte.tex
\stopbackmatter
\stoptext

Best regards: OK


On 22 May 2014, at 13:50, Werner Hintze <we.hintze@gmail.com> wrote:

> This is the problem: It works, but I don’t unterstand why. I make just my first steps with ConTeXt…
> 
> Anyway: I found out, that this is the best solution:
> 
> \defineconversionset[frontpart:pagenumber][][romannumerals]
> \defineconversionset[bodypart:pagenumber][][numbers]
> \defineconversionset[backpart:pagenumber] [][characters
> \defineconversionset[appendix:pagenumber][][Characters]
> \setupuserpagenumber[numberconversionset=pagenumber,way=byblock]
> Now it’s not nessecary to reset the pagenumber.
> 
> Thanks for the hint about the Sample texts.
> 
> Best regards.
> 
> WH
> 
> On 22 May 2014, at 12:56, Otared Kavian wrote:
> 
> On 22 May 2014, at 12:44, Werner Hintze we.hintze@gmail.com wrote:
> 
> Thank you once more! This looks better. It’s a pity that such things are not »wikified«… ;)
> 
> Once you think you have well understood something do not hesitate to wikify it…
> 
> But there is a new surprise: What is knute.tex, ward.tex and tufte.tex? Are there more of those texte? And how does one finde them?
> 
> Look where you have installed the ConTeXt tree, in the following directory
> 
> tex/texmf-context/tex/context/sample
> you’ll find some other sample files which can be input for testing: they are very useful!
> 
> Best regards: OK
> 
> If your question is of interest to others as well, please add an entry to the Wiki!
> 
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
> archive : http://foundry.supelec.fr/projects/contextrev/
> wiki : http://contextgarden.net
> 
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
> 
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
> archive  : http://foundry.supelec.fr/projects/contextrev/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________