Is the TMCC signal use a variation of the RS232 or RS422 standards?
George
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The TMCC track signal has no relationship to the serial communication standards. It's a FSK signal with a carrier frequency of about 455khz, and it transfers data at a 3,000 BPS data rate. Obviously, the serial port on the command base has a relationship to the serial communication standards, it's operating at 9600 BPS, one stop bit, and no parity.
OK, thanks! FSK?
George
FSK - Frequency Shift Keying. The carrier frequency of the TMCC signal is shifted to denote ones and zeros in the bit stream.
@gunrunnerjohn posted:The TMCC track signal has no relationship to the serial communication standards. It's a FSK signal with a carrier frequency of about 455khz, and it transfers data at a 3,000 BPS data rate. Obviously, the serial port on the command base has a relationship to the serial communication standards, it's operating at 9600 BPS, one stop bit, and no parity.
9600 baud. Gee, I remember when I thought that was fast! Of course, I looked like this, too. 
George
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I remember when 300 baud was fast. 
Remember putting the phone on the 300 Baud modem cradle?
Only too well I remember that! Then I got a wired 1200 baud Hayes modem and thought I was king of the world! 
My first assignment was programming a GE teletype terminal with a paper tape reader to read 8-bit input (Packed Image Mode). DEC-10 assembler and Fortran.
George
