Meridian America 61 Manual De Usuario

 

 

 

 

The QPC578 Integrated Services Digital Line Card (ISDLC) is a

voice and data communication link between a Meridian SL-1 and the
Meridian 

 series of digital telephones. When a digital

telephone is equipped with the data option, an asynchronous ASCII
terminal or PC can be connected to Meridian 

 through the digital

telephone. The ISDLC circuit pack supports voice only or simultaneous
voice and data service over a single twisted pair of standard telephone
wiring. This practice describes the ISDLC. For more information on
Meridian digital telephones, see 553-2201-110 and 553-2201-111 for the
M2000 series telephones, the 553-2201-115 for the M3000 telephone,+
and the 553-2201-113 for the M2317 telephone.

To use the ISDLC, the following Meridian SL-1

requirements must be met:

l 

Double Density Peripheral Shelves must be equipped (one shelf per
loop)

. Generic X11, Release 7 (or later) or Generic 

 Release 10 

later) software must be running.

l 

Quadruple Density loops must be defined in hardware 

 set to

ON on the associated Peripheral Buffer) and software (OVL 17)

l 

At remote locations using Remote Peripheral Equipment (RPE),

ISDLC packs must be 

 series C or higher.

1.03 The QPC578 ISDLC is equipped with eight identical line circuits.
Each line circuit provides a multiplexed voice, data and signaling path
to and from digital apparatus over a 2-wire full duplex 512 KHz Time
Compression Multiplexed (TCM) digital link.

Once every 125 

 the

ISDLC transmits a 23 bit message to a digital telephone. At the end of

the 23 bit message a 2.7 bit guard band delay is inserted. Then the

digital telephone begins transmitting a similarly formatted 23 bit

message to the ISDLC. Each 23 bit message consists of:

l 

start (1 bit)

l 

voice signaling (1 bit)

l 

voice 

 (1 bit)

l 

PCM voice (8 bits)

l 

data signaling (1 bit)

l 

data valid (1 bit)

l 

data (8 bits)

l 

parity (1 bit)

l 

stop (1 bit)

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