XBee SX module coordinated cyclic sleep mode

Hi. I’m testing some 900 MHz XBee SX modules with the XBIB-U-SS test boards. I’m trying to establish a DigiMesh network with a single synchronous sleep coordinator (my base) and N (so far one) leaf nodes. I’m using XCTU for testing.

I’m trying to understand the sleep modes, and I don’t seem to be able to use the DIO9 sleep indication functionality or the device doesn’t actually sleep at all.

My base configuration is:
BR = 0 (10 kbps)
CE = 0 (Standard Router)
SM = 8 (synchronous cyclic sleep mode)
SO = 0x21 (bit 0 = preferred sleep coordinator, bit 5 = disable coordinator rapid sync deployment mode)
SP = 1F4 (5000 ms)
ST = 7D0 (2000 ms)
NH = 0x04 (Network Hops)
NN = 0x03 (Network Delay Slots)
MT = 0x03 (Broadcast Multi-Transmits)
D9 = 1 (ON/Sleep)

My node 1 configuration is:
BR = 0 (10 kbps)
CE = 1 (Indirect message coordinator)
SM = 8 (synchronous cyclic sleep mode)
SO = 0x02 (bit 1 = non-sleep coordinator)
SP = 32 (500 ms - this should be overridden by the network)
ST = 7D0 (1500 ms - also this)
D9 = 1 (ON/Sleep)

The devices see each other; I can transmit data between them using the API console (strangely, I see no off-times here, which suggest no node is sleeping). The RSSI indicator turns on for three seconds on a 36 second cycle. I expected it to go on a 2/7 second cycle. Accordingly, DIO9 is always high (LED is always on). If I change the D9 setting I can turn on/off the LED manually, but it seems it doesn’t follow the sleep status of the modules or the modules don’t sleep at all.

After some stabilization time, Node 1 shows SS=0x1040 (reserved + deployment mode). The base shows SS=0x42 (deployment mode + sleep coordinator).

Both modules are running firmware 9004 (latest); device label says “XB9X-DMUS-001-revD”.

My questions are:

  1. Are the devices actually sleeping? (I expect at least node 1 to sleep).
  2. If 1 is yes, why DIO9 doesn’t follow the sleep status?
  3. Why the strange cycle time for the RSSI LEDs? Shouldn’t it be 7 seconds instead of 33?
  4. How can I get the modules to sleep? Is anything missing from my config?

Thanks in advance,