File AP72-04 iss 4
GSGC6 INSTALLATION
GENERAL
The GSGC6 is a 1U subrack designed to be fitted in an equipment rack or apparatus room.
Although there are some indicators and 3 controls on the front panel, it is not necessary to
access these.
MAINS
An IEC mains connector with a retaining clip is provided on the rear panel. The mains earth
is internally connected to the metalwork. A terminal binding post is also provided adjacent to
the mains connector to permit additional earth bonding.
ISDN CONNECTION
Connection to the ISDN2 S bus is via a standard RJ45 socket. A 3 metre lead is provided with
the GSGC6. If a longer lead is required or an extension is fitted to the ISDN2 point be very
sure to use only cables to the correct specification.
AUDIO
Audio circuits are balanced zero level on 3pin XLRS. The inputs are fixed sockets and the
outputs are fixed plugs. Maximum digital code is sent with a +14dBu signal. The GSGC6
does not contain a limiter so any input greater than +14dBu will be clipped by the digital
system. It is worth noting that digitally clipped signals can often upset the codec at the other
end of the circuit. This is particularly true for G722 codecs with statistical frame locking. It is
therefore good practise to ensure that the levels sent to the GSGC6 do not 14dBu.
CONTROL
Control of the GSGC6 can be from a computer system or from our dedicated controllers type
GSGC7. The control ports are RS232 type ports on a 9 pin D fixed sockets wired to the IBM
PC standard. A separate control port is provided for each codec position.
DC LOOPS
A further 15pin D fixed plug is provided for each port. These provide various loop closures
and can be used to operate lamps or other studio equipment. In addition switches can be fitted
in the studio to:- 1)send a programmable DTMF tone 2) 'Hang Up' the terminal adapter 3) dial
a previously stored ISDN number.
AUX DATA
When the GSGC6 is fitted with an MPEG Codec an extra 9 pin D fixed socket is fitted. This
is the Aux Data connector and provides an RS232 type data path to a similarly equipped
codec at the other end of the ISDN circuit. It operates at a fixed 9600 baud and is compatible
with some other manufacturers codecs.
CODECS
The GSGC6 will normally be fitted with the codecs as ordered with the equipment. It is
however simple to add or change the codecs. This can be done by removing the top cover of
the GSGC6. The codecs are mounted one above the other and are connected to the main PCB
via 60pin IDC leads. The lower codec is connected to port 1 and the upper codec is connected
to port 2.
