December 2007
Page 41
90-005-0003 Rev X01
50 Watt Ka Feedmount BUC User Manual
State 3 - Device Data State
In State 3, a device is engaged in receiving the command and associated data bytes
sent by a master/controller. A device will exit State 3 and enter:
1. State 4 (device data error state) if ETX byte is received signifying the end
of data in the message.
2. State 1 (device idle state) if invalid command, or data character, or
incorrect number of data bytes is received.
State 4 - Device Data Error State
In State 4, a device is waiting to receive a checksum byte which tests the
transmitted message for errors. A device will exit state 4 and enter:
1. State 5 (command execute state) if a checksum byte is true (received LRC
value of checksum byte equals LRC value computed by a device during
message reception)
2. State 1 (device idle state) if a checksum byte is false (received LRC value
of checksum byte does not equal LRC value computed by a device during
message reception).
State 5 - Command Execute State
In State 5, a device, having completed a reception of SAbus message, executes a
device's function specified by a command byte. A device will send and appropriate
response message to a master/controller within 100 milliseconds after receiving the
last character of the message. A device will always exit State 5 and enter State 1 -
Device Idle State.
