AeroComm user manual CL4424 User’s Manual Hardware Flow Control

CL4424 User’s Manual

2.3Hardware Flow Control

Often, the host device can send data to the CL4424 faster than it can be sent over the RF. The CL4424 has a 256 byte buffer to store data before sending it over the RF. If the host device is sending data faster than the CL4424 can send it out, eventually, the buffer will fill up. If the host device continues to send data while the CL4424 buffer is full, that data will be discarded. To avoid this situation, the CL4424 will de-assert CTS as a warning that the buffer is filling. The host device should stop sending data. When the CL4424 is able to free some buffer space, it will assert CTS and the host device can continue sending data. Similarly, if RTS is enabled in the CL4424, the host device can throttle the CL4424 by de-asserting RTS. Note: CTS is always enabled by default. RS-485 Interface does not support Hardware flow control and RTS mode should not be enabled on a RS-485 CL4424.

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