AN118
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On the other hand, since the 8 LSBs of the Sync ID are used as the Factory Code, during the manufacturing process the counting
of the Sync ID shall start on the bit 8. The CMOSTEK manufacturing tool is able to map the user-defined ID to the correct position
of the Sync ID in the device. If the users want to design their own Sync ID management tool, please consult CMOSTEK for more
details.
In 1527 mode, the Factory Code is not supported, and therefore the 8 LSBs of the Sync ID are used as part of the Sync ID, and
can be studied as part of the Sync ID.
In 2262 mode, the ID Study is not supported and therefore the Factory Code is not supported.
6.3 Study RSSI TH
This threshold is an 8-bit code that is comparable to the 8-bit RSSI. During the study process, the device firstly detects if the RSSI
of the incoming signal is higher than this threshold. If not, the study is forbidden. Therefore, the Study RSSI TH helps the user to
limit the communication distance in which the device can study the Sync ID from the transmitter.
It is suggested for the user to perform on-field testing and adjustment of the transmitting power of the Tx, and the Study RSSI TH
of the Rx to define the communication distance for ID study. The RFPDK for CMT2250A provides a “RSSI Scan” function to
perform the on-line scanning of the RSSI. Once the “RSSI Scan” window is opened, it dynamically displays the real-time RSSI
level detected by the device. The user can use this information to setup the proper value of the Study RSSI TH. Please refer to
“AN115 Pairing CMT2150A and CMT2250A” for more details of adjusting the study distance.
Please note that this threshold only impact the ID studying, not the normal communication.
6.4 Study Time Window
In many applications, the Tx and Rx pairing (ID Study) is only performed in a short time period after the devices are powered up.
This parameter defines the time window in which the study is allowed after the power up of the device. As one of the options, the
window can always be opened and therefore no time limitation is there for studying. Please refer to “AN115 Pairing CMT2150A
and CMT2250A” for more details of setting this parameter.
