2.8.6.2 Wake Check OK (WCO)

After the receiver is initialized and running, the RF input is checked for a valid signal. The detection of such a signal is called wake check OK (WCO). Several check conditions can be enabled independently for path A and path B of each service in the eepServices.SOT1x variables:

• Manchester coding check (MANOEx)
• Symbol timing check (SYTOEx)
• Modulation amplitude check (AMPOEx)
• Carrier check (CAROEx)
• RSSI range check (RROEx)
• Wake-up pattern check (WUPEx)
• Wake check OK from other path (WCOxOE)

By default, the Manchester, symbol timing, modulation amplitude, carrier (FSK only) and wake-up pattern checks are activated as a WCO condition. The SFID check cannot be activated as a WCO condition, but still the SFIDEx bit must always be set to ‘1’ to avoid erroneous behavior of the internal state machine of the ATA8510/15.

The functionality and configuration of the checks is described in detail in Telegram Settings and Signal Checks.

If any of the following checks is enabled as a WCO check in the SOT1x variable, the corresponding EOT1x check (compare End of Telegram (EOT)) must be activated: Manchester coding, symbol timing, modulation amplitude, carrier check or RSSI range check.

A WCO is triggered as soon as all enabled checks have passed; therefore, the time period from receiver start-up until a WCO is determined by the longest check.

If a WCO is received on one path, the other path is switched off unless the eepServices.rxSysSet.PathValidAfterSOT_ENA EEPROM variable is set to ‘1’. Then, the other path is switched off not before the SOT event. If both paths receive the WCO/SOT event at the same clock cycle, path A wins.