Editing IRIG timecode (section)

==IRIG J timecode==
IRIG standard 212-00 defines a different time-code, based on [[RS-232]]-style [[asynchronous serial communication]].
The timecode consists of [[ASCII]] characters, each transmitted as 10 bits:
* 1 start bit
* 7 data bits
* 1 [[odd parity]] bit
* 1 stop bit
The on-time marker is the leading edge of the first start bit.

IRIG J-1 timecode consists of 15 characters (150 bit times), sent once per second at a baud rate of 300 or greater:

 <nowiki><SOH>DDD:HH:MM:SS<CR><LF></nowiki>

* SOH is the ASCII "start of header" code, with binary value <code>0x01</code>.
* DDD is the [[ordinal date]] (day of year), from 1 to 366.
* HH, MM and SS are the time of the start bit.
* The code is terminated by a [[Newline|CR+LF]] pair.

At the end of the timecode, the serial line is idle until the start of the next code.  There is no idle time between other characters.

IRIG J-2 timecode consists of 17 characters (170 bit times), sent 10 times per second at a baud rate of 2400 or greater:

 <nowiki><SOH>DDD:HH:MM:SS.S<CR><LF></nowiki>

This is the same, except that tenths of seconds are included.

The full-timecode specification is of the form "IRIG J-''xy''", where ''x'' denotes the variant, and ''y'' denotes a baud rate of 75×2<sup>''y''</sup>.

Normally used combinations are J-12 through J-14 (300, 600, and 1200 baud), and J-25 through J-29 (2400 through 38400 baud).

{| class="wikitable"
|-
! Combination J-''xy'' !! variant (''x'') !! ''y'' !! 2<sup>''y''</sup> !! Baud = 75 × 2<sup>''y''</sup>
|-
| J-12|| 1|| 2|| 4|| 300
|-
| J-13|| 1|| 3|| 8|| 600
|-
| J-14|| 1|| 4|| 16|| 1200
|-
|colspan=5|
|-
| J-25|| 2|| 5|| 32|| 2400
|-
| J-26|| 2|| 6|| 64|| 4800
|-
| J-27|| 2|| 7|| 128|| 9600
|-
| J-28|| 2|| 8 || 256|| 19200
|-
| J-29|| 2|| 9|| 512|| 38400
|-
|}