CC1310: WMBus Postamble is 3 out of 6 Encoded

Hi Gareth,

Someone has been assigned to take a look at this.

Regards,

Sid

The engineer with the best overview of WMBus is out the rest of the week. But based on your question I get the impression that you are using the WMBus stack? Are you actually looking at the postamble since according to https://e2e.ti.com/support/wireless-connectivity/sub-1-ghz-group/sub-1-ghz/f/sub-1-ghz-forum/1042018/cc1310-wmbus-patch-question-to-postamble the postamble is added by the stack and not directly by CC1310.

Yes I am using the WMBus stack.

I am looking at the MCE_GPO0 signal using the method described here, https://software-dl.ti.com/simplelink/esd/simplelink_cc13x0_sdk/3.20.00.23/exports/docs/proprietary-rf/proprietary-rf-users-guide/rf-core/signal-routing.html. If I have understood correctly, this is the digital signal just before modulation, so will include anything added by the stack.  When I decode the signal I see 0x55 or 0xAA at the end of the message, depending on whether the last CRC is odd or even, as expected.  However, this is 3 out of 6 encoded and I was expecting it to be sent as is.  Is that assumption correct?

Since the postamble is added by the stack you need to check with stackforce why the postamble is 3 of of 6 coded. As I read the standard it's just the data that should be 3 out of 6 coded and not the postamble. 

On the other hand, most radios in the filed today will discard anything after the CRC and the postamble should not have any practical impact.