Self-Electing Subnet Services issue

Hello,

I'm using LDMS 207.3.2 and I want to use OS Provisioning.

I have a problem with Self-Electing Subnet Services. The PXE Representative elected is not a device that always

works : its state is often "deactivated" and I can't change it on my own.

I would like to have a single PXE Rep on my subnet (for instance, a computer I have chosen before, with PXE service  activated in client connectivity). How can I do that ?

Thanks for help.