Input buffers:
The MAC Processor reads the packet and checks if the CRC is correct. If it is, the packet is received in a network input buffer and its destination address is examined by the Network processor. If the packet is addressed to the node, it is copied into an application input buffer and the network input buffer is freed. If no application input buffer is available (because the application is not processing its packets fast enough), then the packet is discarded and no acknowledgement is sent.
Output buffers:
The number of output buffers becomes a factor in response time when a node can generate outgoing packets faster than the network can take them. What happens in this case, is that several outgoing packets back up in the output queue. If the network variable is declared as non-synchronous, the value is sent on the network when the next output buffer is available. If the program updates the variable again before that time, only the most recent value will be sent. A synchronous output network variable causes the application to wait for an output buffer is none is available.
The Neuron Chip is capable of generating 300 packets per second. At lower data rates or during network saturation, this number of packets can easily overwhelm the ability of the network to accept packets. For this reason, it is always important to know how many packets per second the application can generate as this dictates the network data rate required.