qx is an extension of qc which is 15 bits long instead of 2 bits.
In the following, the overview of the qx structure:
- High Byte: Industrial Edge Specific Information
- Bit 15: Reserved
- Bit 14...12: Flags
- Bit 11...8: Extended sub-status
- Low Byte: Quality code according to PROFIBUS PA / OPC DA
- Bit 7...6: Quality
- Bit 5...2: Sub-status
- Bit 1...0: Limits