Technical data

Installation & Operation Manual GM-TTT
Page 32
4 BBC All binary groups are used for the date, with a special format according
to EBU Technical Information I29-1995 (BBC format). The date is BCD-coded and
assigned to the binary groups as follows:
BG1 reserved bits = 0
BG2 units of the day 4 bits, lsb = bit 12
BG3 units of the month 4 bits, lsb = bit 20
BG4 tens of the day 2 bits, lsb = bit 28
tens of the month 1 bit = bit 30, bit 31 = 0
BG5 reserved bits = 0
BG6 units of the year 4 bits, lsb = bit 44
BG7 reserved bits = 0
BG8 tens of the year 4 bits, lsb = bit 60
5 DATE-2 All binary groups are used for the date of the internal clock, BCD format: day =
groups 7+8 (“hours“), month = groups 5+6 (“minutes“), year = groups 1 to 4
(“seconds” and “frames“). The year is coded in four digits, valid from 1998 to
2097. The reference input of the date may have the year only with two digits, so
the following rule applies: with the two digits coded year < 98 the century will be
20, else 19. After power-on the unit starts with the date 1.1.2002. Look at the
table of the end of this chapter for a survey of the date formats.
6 DATE-3
7 DATE-4
8 DATE-5
9 DATE-6
There are more formats of the date selectable, similar to the selection “2 DATE“.
Please look at the table of the end of this chapter for a survey of the date formats.
A DATE-7 Conforming to a “TVE” specification:
• The arrangement of Day, Month and Year conforms to “8 DATE-5”.
• BG1 gets an appointment code = $8, BG8 gets a check sum = bit-wise
complement of the sum (modulo-16) of BG1 to BG7.
• Additionally the binary group flag BGF2 is set to 1.
b OFF nn Coding of date and a time offset, conforming to LEITCH CSD-5300 format with
Auxiliary Offset. The binary groups are used for the date as described under “4
BBC”. Additionally an offset is encoded in 30-minute increments. 6 bits in binary
form are split into two 3-bit groups and are inserted into the reserved binary
groups BG5 and BG7:
BG5 offset, 3 lower bits 3 bits, lsb = bit 36
BG7 offset, 3 upper bits 3 bits, lsb = bit 52
This allows an offset in the positive direction of up to 23 hours 30 minutes, or 47
half hour steps (101111 in 6-bits binary form). Devices decoding these bits add
this offset to the time information of the time code. The date coded in the binary
groups is not coupled with that offset, i.e. the date changes at 24 o’clock of the
time information of the time code.