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RC4000 Antenna Controller
Appendix REM
Remote Control Option
Message Delimiters
A command message begins with STX (02 hex). A reply begins with ACK (06 hex) or NAK (15 hex)
depending on the result of the command execution. All messages end with the ETX (03 hex), the ASCII
End-of-text control character, followed by the Checksum byte.
Address Byte
The device address (ADDR) must be a valid ASCII printable character between 49 (31 hex) and
111 (6F hex); thus, 63 addresses are possible.
Command Byte
The command byte (CMD) immediately follows the device address and specifies one of several possible
commands for a particular device.
Checksum Byte
The last character of any message is the Checksum byte (CHK). This character is simply the bit-by-bit
exclusive OR of all characters in the message starting with the STX character through the ETX character.
This forms a Longitudinal Redundancy parity check over the entire message.
Message Timing
The NAK or ACK reply does not signify that a function has actually taken place, but only that the message
was received and understood. The user should query the controller later to see if the command was
actually carried out, or is still in progress.
Command Restrictions
All RC4000 devices will respond to a command "0" (30 hex) with 6 data bytes of ASCII characters in the
following form:
ACK
ADDR
30h
4
K
D
.
D
D
ETX
CHKSUM
1
2
3
where D
D
D
are ASCII characters representing a software version number (e.g. 1.12).
1.
2
3
REM-3
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