# Negative number in ARINC-429

I'm a little bit confused by representation of negative number in ARINC-429.
Let's consider the following example:

1. Significant bits is equal to 7 (it does not count sign bit),

2. Resolution is equal to 1,

3. DATA section has to represent -1 value.
Initially I thought that DATA section is represented as follows:

1 1 1 | 1 1 1 1 | 1 0 0 0 | 0 0 0 0 | 0 0 0 0


But I'm confused by sensor documentation. There sign bit is not in DATA section and I started to think that maybe bits 29-11 should look like that:

1 0 0 | 0 0 0 0 | 1 0 0 0 | 0 0 0 0 | 0 0 0 0


Which way of thinking is correct?