RESEARCH CONCEPTS RC2000C Manual page 83

RC2000C Polar Tracking Antenna Controller
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Mnemonics
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STX
ETX
Checksum LRC byte
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States Description
State 1 (Slave Idle State). In State 1, a slave is ready to receive a new message, and therefore, must
complete any previous message reception. A slave always powers on in State 1.
A slave will exit State 1 and enter State 2 (Slave Addressed State) only if STX byte is received.
State 2 (Slave Addressed State). In State 2, a slave is waiting to receive the address byte, the second byte of a
command message.
A slave will exit State 2 and enter:
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Table 1. State Diagram Mnemonics
Start-of-Text ASCII control character, used as a header in command messages to
identify the beginning of a new message.
End-of-Text ASCII control character, used as a termination character in messages to
identify the end of data.
(Longitudinal Redundancy Check) is a last byte in the message data block. The value
of LRC byte is the exclusive OR of all message bytes including the STX and the ETX
bytes and is used to detect errors during transmission of data.
Appendix E Communications Protocol
Description
77
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