MDR24X User’s Manual
10/26/2006
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2.3
Hardware Flow Control
Often, the host device can send data to the MDR24X faster than it can be sent over the RF. The
MDR24X has a 256 byte buffer to store data before sending it over the RF. If the host device is
sending data faster than the MDR24X can send it out, eventually, the buffer will fill up. If the host
device continues to send data while the MDR24X buffer is full, that data will be discarded. To
avoid this situation, the MDR24X will de-assert CTS as a warning that the buffer is filling. The
host device should stop sending data. When the MDR24X 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
MDR24X, the host device can throttle the MDR24X 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 MDR24X.
