A robot-assisted surgical system comprising: a pair of nodes (110, 120, 130, 140) coupled to each other with a serial data link, the serial data link being configured to transfer data having different priority types between the nodes, each node including: a programmable processor operable to execute instructions; a first data buffer coupled to the programmable processor, the programmable processor being operable to transfer first-priority data received by the node over a first serial data link to the first data buffer responsive to the instructions, the first data buffer being for use with only the first-priority data, the first-priority data being messages having been assigned a first priority type and including commands to control the movement of a robotic arm; a second data buffer coupled to the programmable processor, the programmable processor being operable to transfer second-priority data received by the node over the first serial data link to the second data buffer responsive to the instructions, the second data buffer being for use with only the second-priority data, the second-priority data being messages having been assigned a second priority type and including at least one of non-critical status information or error-logging information; and transmission logic coupled to the first and second buffers and to the serial data link, the transmission logic being operable to transmit the first-priority data preferentially over the second-priority data over the serial data link in accordance with a messaging protocol. a pair of nodes (110, 120, 130, 140) coupled to each other with a serial data link, the serial data link being configured to transfer data having different priority types between the nodes, each node including: a programmable processor operable to execute instructions; a first data buffer coupled to the programmable processor, the programmable processor being operable to transfer first-priority data received by the node over a first serial data link to the first data buffer responsive to the instructions, the first data buffer being for use with only the first-priority data, the first-priority data being messages having been assigned a first priority type and including commands to control the movement of a robotic arm; a second data buffer coupled to the programmable processor, the programmable processor being operable to transfer second-priority data received by the node over the first serial data link to the second data buffer responsive to the instructions, the second data buffer being for use with only the second-priority data, the second-priority data being messages having been assigned a second priority type and including at least one of non-critical status information or error-logging information; and transmission logic coupled to the first and second buffers and to the serial data link, the transmission logic being operable to transmit the first-priority data preferentially over the second-priority data over the serial data link in accordance with a messaging protocol. a programmable processor operable to execute instructions; a first data buffer coupled to the programmable processor, the programmable processor being operable to transfer first-priority data received by the node over a first serial data link to the first data buffer responsive to the instructions, the first data buffer being for use with only the first-priority data, the first-priority data being messages having been assigned a first priority type and including commands to control the movement of a robotic arm; a second data buffer coupled to the programmable processor, the programmable processor being operable to transfer second-priority data received by the node over the first serial data link to the second data buffer responsive to the instructions, the second data buffer being for use with only the second-priority data, the second-priority data being messages having been assigned a second priority type and including at least one of non-critical status information or error-logging information; and transmission logic coupled to the first and second buffers and to the serial data link, the transmission logic being operable to transmit the first-priority data preferentially over the second-priority data over the serial data link in accordance with a messaging protocol.