How to check the iterative history of convergence and change convergence criterion in glmmadmb

I am using glmmadmb to fit negative binomial mixed effects model to my data. However it fails to converge sometimes. I want to understand what is causing the failure of convergence by first of all check whether it really fails to converge or just converges very slowly? when I fit the data using was glmmmix? the iteration history reply shows that my model does converges but fail to meet the default convergency criteria. When I relax the convergence criterion, it converges well.  

Is there anyway I can find the iteration history in glmmadmb as well? And can I change the default convergence criterion?

Thanks!

Jing

Jing qiu