Antona Corporation (818)783-4299 URL:http://www.antona.com
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Appendix A - Clock Protocol
The RS422 serial output to the remote mounted clock(s) is fixed at 2400 Baud, 8 data
bits, one stop bit and no parity. Transmission of time-of-day to all clocks is
synchronized at 1 second intervals. Individual brightness settings are transmitted
addressed to each clock 1/2 second after a time-of-day transmission. Data, whether
time or control information is fixed at 6 bytes as follows:
Byte #
Description
1
Sync Code (CCH)
2
Unit Address - 00H to 08H (All=80H)
3
Control Code*
4
Data byte 1 (hours/brightness)
5
Data byte 2 (minutes)
6
Checksum - sum of bytes 2-5 modulo 8,
1's compliment
* - the control codes are as follows:
21H = set clock time of day with bytes 4/5 (packed BCD)
20H = set clock brightness with byte 4 lower nibble (binary)
31H = set clock test LED mode - turn all LEDs on
A typical serial transmission of time data would be as follows:
CCH 80H 21H 12H 34H 0AH
This would display "12:34" on all connected and powered ANC-7020 units.
