Currently CNMaestro is not managing PMP 450 series just yet. It only manages de EPMP 1000 and cnPilot devices. It will be nice to be able to manage that and also de PMP 100 as well
450(i) support is def on the roadmap for Q1 next year IIRC. PMP100 (and presumably all older platforms) will not be supported. The radios simiply don't have enough memory to support the cnMaestro agent process.
Eric's right (mostly)... planning for support for 450 in Q2, 2016. Stay Tuned!
PMP 450 is manageable by cnMaestro now.