900MHz AP and SM version compatibility

I use a 900 MHz AP and a few subscriber modules in a mobile application. Recently I needed a couple of extra SM’s and had them sent to the site. The new SMs refused to register with the AP. After fighting with it for a while, the only thing that I can see that is different from the older SMs that work fine is the software version is different. I believe the older AP and SMs are 6.x and the newer SMs were 8.x.

Do I need to downgrade the newer SMs or upgrade the older AP and SMs to get them to all work together?


assuming the new SM’s are P10 hardware you can;t downgrade below 8.x so you’ll have to upgrade old ap and sm’s.

You’ll need to upgrade the older equipment to newer firmware. I’m willing to bet your installation is running software scheduling. New P10 modules only support hardware scheduling.


You will be able to upgrade your current subscriber units to the latest firmware, but you will need to purchase a new AP in order to run hardware scheduling at the access point level.

You DO NOT NEED to purchase new ap. All 900mhz equipment was P9 and above which are capable of running hardware scheduling. I believe wifiguy is mistaken.

In order to change AP to hardware scheduling, on the configuration page just check the hardware scheduling option and save and reboot. Be sure to change SM's before hand as they will not re-register if they aren't running H/W scheduling as well.

Yep, I am mistaken. I forgot that 900MHz was P9 and above.

You should be able to switch your AP to hardware scheduling and the new units should register. Make sure ALL of your SMs are set for hardware scheduling as well.

I’d also recommend getting the latest firmware on there. 8.x had a lot of problems. 9.4 is the latest stable release.

900 is all Advantage.

Manually upgrade each SM to 7.3.6 and there will be the option to switch to HW scheduling.

Thanks to everyone for responding to this and sorry I haven’t responded sooner. All I had to do was change the AP to hardware scheduling and both the new and old SMs worked beautifully.