Cisco Systems PA-4T manual Synchronous Serial Overview

Synchronous Serial Overview

The following example of the show diag slot command shows a PA-4T+ in port adapter slot 1 in a Cisco 7200 series or a cisco uBR7200 series router:

Router# show diag 1

Slot 1:

Mx serial port adapter, 4				ports
Port adapter is analyzed
Port adapter insertion			time 02:19:52 ago
Hardware revision 1.0					Board revision UNKNOWN
Serial number		3701161			Part number			73-1577-03
Test history		0x0			RMA number			00-00-00
EEPROM format		version 1
EEPROM contents (hex):
0x20: 01	0C	01 00 00	38	79 A9	49 06	29	03 00 00 00		00
0x30: 05 00		00 00 FF	FF	FF 00	FF FF FF FF FF FF FF FF

The following example of the show diag slot command shows a PA-4T in port adapter slot 1 in a

Cisco 7100 series router:

Router# show diag 1
Slot 3:
Serial port adapter, 4		ports
Port adapter is analyzed
Port adapter insertion		time 02:19:52 ago
EEPROM contents at hardware discovery:
Hardware revision	1.0		Board revision	A0
Serial number	37296561		Part number	73-1556-04
Test history	0x0		RMA number	00-00-00
EEPROM format version 1
EEPROM contents (hex):
0x20: 01 11 01 00 00		A4 19	EC 49 06 98 04 00	00 00 00
0x30: 50 00 00 00 98		10 21	00 FF FF FF FF FF FF FF FF

Synchronous Serial Overview

The PA-4T+ provides four channel-independent, synchronous serial ports that support full-duplex operation at T1 (1.544-Mbps) and E1 (2.048-Mbps) speeds. Each port supports any of the available interface types: Electronics Industries Association/Telecommunications Industries Association (EIA/TIA)-232, EIA/TIA-449, V.35, X.21, and EIA-530.

EIA/TIA-232, which is by far the most common interface standard in the U.S., supports unbalanced circuits at signal speeds up to 64 kbps. EIA/TIA-449, which supports balanced (EIA/TIA-422) and unbalanced (EIA/TIA-423) transmissions, is a faster (up to 2 Mbps) version of EIA/TIA-232 that provides more functions and supports transmissions over greater distances. The EIA/TIA-449 standard was intended to replace EIA/TIA-232, but it was not widely adopted.

Note The EIA/TIA standards were referred to as recommended standards called RS-232 and

RS-449 prior to their acceptance by the ANSI committee.

The resistance to convert to EIA/TIA-449 was due primarily to the large installed base of DB-25 hardware and to the larger size of the 37-pin EIA/TIA-449 connectors, which limited the number of connections possible (fewer than is possible with the smaller, 25-pin EIA/TIA-232 connector).

EIA-530, which supports balanced transmission, provides the increased functionality, speed, and distance of EIA/TIA-449 on the smaller, DB-25 connector used for EIA/TIA-232. The EIA-530 standard was created to support the more sophisticated circuitry of EIA/TIA-449 on the large number of existing EIA/TIA-232 (DB-25) hardware instead of the larger, 37-pin connectors used for

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