Table 6-6 Checksum Example Error

[prwatE120]

In section 6.2.11 Table 6.6 we have an example of checksum usage.

It happens to use of a GET_COMMAND: STATUS_MESSAGES and shows in slot #24 a value of 0xFF for the paramater data STATUS_ERROR.

HOWEVER the Status Type define for STATUS_ERROR is shown in Table A-4 as 0x04.

How did I find this ??

A controller (by others) sent me a GET:STATUS_MESSAGES with 0xFF in the paramater data, which I rejected with a
NACK: NR_DATA_OUT_OF_RANGE, since the only valid values (from Table A-4) are 0x00 thru 0x04.

I suggest we review this (and other task group posts) in Dallas before making some of this knowledge public via this forum

regards

[sblair]

That example is incorrect. The correct value for STATUS_ERROR is 0x04. The correct value for SC_SUB_MESSAGE is 0x01.

With the STATUS_ERROR of 0x04 and SC_SUB_MESSAGE, the correct Checksum would be: High Byte=0x06, Low Byte=0x69.