ymodem in transparent mode, unicast setting

using xbee pro s2b modules on both ends.
Coordinator AT V.20A7
End Device AT V.28A7
coordinator DH, DL set to the end device SH, SL values (unicast mode).

Using windows 7 hyperterminal to the coordinator.
The end device is talking to a Persistor CF2, using the picodos ‘yr’ =ymodem receive file command.

To get ymodem to work (coordinator to end-device) required setting the sleep mode SM=1 on the end-device…probably could have done it with a longer sleep mode?

9600 baud had an effective through-put of ~4k baud.

Started this thread with the ymodem command failing until I set SM=1. The ymodem end-device to coordinator worked fine.

I assume you changed SM=4 to become SM=1. With Sm=4 it was dropping data because it would sleep on/off, so you cut your bandwidth greatly. I’m guessing that with SM=1, your end-device is being fooled to always be awake.

Why do you even have an end-device if it doesn’t sleep? End-devices are hugely chatting, eating a lot of radio bandwidth if they don’t sleep. Literally, with 28A7 fw in there, the coordinator (aka: the parent) does NOT send the data to the end-device, the end-device polls the parent every 100msec for some data (unless SM=4, then it wakes every 320msec and does it). So you’ll allow at most 10 data packets per second, so I have a hard time believing you even saw 4kbaud. I’d expect closer to 800 baud :slight_smile:

Anyway, if your 2nd device doesn’t sleep, just put AT Router fw 22A7 in it, then it is always awake and the two can talk in real-time, instead of this slow polled method.