I am using XBee S2C modules with DigiMesh firmware (9000, 2.4) - I am curious as to what is the maximum payload size in API Mode (2, escaped)? Digi site claims “Up to 256 Bytes” (https://www.digi.com/blog/networking/what-are-the-differences-between-digimesh-and-zigbee-mesh/) - I’ve seen posts online claiming 84 bytes. But NP returns 49. Who is should I trust? If it is indeed 49, any way to increase?
NP reports the value in HEX characters. The 256 bytes in using API mode.
Ok, I feel pretty dumb about missing the hex part, but still, I am in API mode and 73 is not even close to 256. What is even odder is that when I flash the Zigbee Mesh firmware (505F), I do get FF(256) for NP - which is exactly the opposite of what I expect according to the link above.
What firmware are you working with? Is it: 8025.15.4, Digi Mesh 2.4 or Zigbee? It does make a difference.
I am getting NP of 0x49(73) from DigiMesh(9000) and 0xFF(256) from ZigBee(505F). I am trying to evaluate those two against each other and one of the big benefits of DM according to the link above was supposed to be a much larger packet size, but I am seeing the opposite, at least according to NP parameter. Trying to understand if I can trust the NP parameter.
What is the full part number for the 900 MHz product you are looking at?
I think the confusion comes from “9000” number - that is the firmware version of DigiMesh firmware, not frequency. As stated in original message, they are 2.4GHz S2C’s - specific ones I am using right now are S2CTH (XB24S2CZ7SIT-004-RevF).
Per the manual it states the following:
NP (Maximum Packet Payload Bytes)
This command applies to the XBee/XBee-PRO S2C DigiMesh 2.4.
Reads the maximum number of payload bytes that you can send in a unicast RF transmission based on the device’s current configuration.
The XBee/XBee-PRO S2C DigiMesh 2.4 firmware returns a fixed number of bytes: 0x49 = 73 bytes.
Yes, and same command exists in Zigbee Mesh with the same description:
>Read the maximum number of bytes that can be sent in a single
>unicast transmission. This number can change based on whether or
>not security is enabled (EE). Broadcast RF packets can support 8 more
>bytes than unicast packets.
So if I believe this metric, I can send up to 73 bytes on DigiMesh firmware and up to 256 bytes on Zigbee Mesh. However that contradicts what most other documentation says. In fact this link states the opposite:
https://www.digi.com/blog/networking/what-are-the-differences-between-digimesh-and-zigbee-mesh/
I am assuming the Zigbee Mesh NP is wrong, and going to go with a shorter payload - but would be nice to know what the reality is
What you are not taking into account is that the link you provided was for different versions of the hardware and related firmware.
The S2C Zigbee does support up to 256 bytes if API mode is used. Also that packet will be broken up into 4 RF packets. Then re-assembled on the receiving side.