Setting of SP and ST facing issue

Hello,

  If I set SP = 0x57E40 which is 1 hour, I want to set ST = 0xFA which is 250ms    but I couldn't achieve this . 
  If I set SP = 0x57E40 automatically ST will set ST = 0x8FC which is 2.3 seconds

how can I achieve ST = 0xFA (250ms) for SP 1 hour??? .I have SET NN=1,NH=2,MT=1
Please help me out ,Thank you in advance

What firmware version and function set are you working with?

Digimesh 2.4 RF module and 300B firmware version

For the length of time you are sleeping, you need to be awake longer. This is to make sure that you receive the sync messages and other house keeping that needs to occur. Check the OS and OW commands for what is needed.

Thank you for your valuable reply, can I get any document where it says ST(awake time) depends (Sleep period) SP it will be more helpful for me
Regards,
Denial

https://www.digi.com/resources/documentation/Digidocs/90002277/#Concepts/c_mode_sync_cyclic_sleep.htm?Highlight=Sleep