Generally speaking, this error should be a very rare occurrence. If this is happening regularly, a review of the circuit design would be recommended to ensure proper design and functionality.
From a software point of view, if no response is received from ANT, the MCU should either retry sending the command - or reset entirely and try the configuration process again. The latter can be easier to implement using a watchdog timer, while the former may be necessary if resetting is not possible or desirable.
ANT will respond to a command right away, hence the response time is gauged by the time it takes to transmit the response message over the serial port. The message response is 7 bytes long. Some examples are shown below. Numbers should be buffered to allow some internal latency, especially if sending commands to a device with open channels.
Serial type: Asynchronous
8 data, 1 start, 1 stop, 0 parity
baud 57600
Min time to get response: [10 bits per byte]*[7 bytes per message] / [57600 bits per second]
= ~1.21 ms
Serial type: Asynchronous
8 data, 1 start, 1 stop, 0 parity
baud 57600
Min time to get response: [10 bits per byte]*[7 bytes per message] / [4800bits per second]
= ~14.58 ms
Serial type: Synchronous
8 data, 1 start, 1 stop, 0 parity
baud 150kHz
Min time to get response: [10 bits per byte]*[7 bytes per message] / [4800bits per second]
= ~0.5 ms
