| | - Premium Cable for Reliable SCSI Performance
- Specified and Tested for Slow, Fast, Ultra, Ultra2, Ultra160 and Ultra320 SCSI Applications
- Wired to Minimize Induced Signal Noise
- Used in Testing Devices for FCC and CE Acceptance
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SCSI Quiet Cable is designed to give maximum performance in all single-ended and differential (HVD and LVD) Slow, Fast, Ultra, Ultra2, Ultra3 and Ultra4 SCSI applications. For reliable system performance, SCSI cable must meet ANSI specifications, which define both electrical and physical parameters. An example is cable pair position within the cable, with signal pairs around the outside and control pairs in the center. Each Paralan SCSI Quiet Cable consists of a shielded cable with 25 (or 34 for wide SCSI) twisted pairs of conductors and two connectors which may be SCSI-1, SCSI-2, SCSI-3, or a combination. The shield is electrically connected to the metal shell of each connector and is isolated from all other signal wires and the connector pins. Cable pair impedance is maintained at 123 ohms, closely matching SCSI termination and thus reducing the potential for reflections. The cabling used for Paralan SCSI Quiet Cable is a high grade UL and CSA-approved, shielded cable consisting of 25 or 34 twisted pairs of multistranded 28 gauge flexible copper wire. Signals are placed within the cable at specified locations to improve noise immunity and to decrease signal
crosstalk. Electrical Characteristics Max. Operating Voltage: 150 Vrms Max. Continuous Current per Conductor @ 25 C: 500 mA Nom. Capacitance between Conductors @ 1 kHz: 10 pF/ft Nom. Conductor dc Resistance @ 20 C: 67 ohms /1000 ft
Nominal Impedance of Pair: 123 ohms (TDR) differential Propagation Delay: 1.54 nS/ft max Pair to Pair Propagation Delay: 0.04 nS/ft max Attenuation: 4 dB/100 ft max @ 10 MHz Connectors: See
connector pinout and housing drawings below. | Physical Characteristics Temperature Rating: -20 to +60 C Insulation Material: Flame retardant PP .034"dia. Jacket Material (Color): PVC (Lt. Gray) Type Shield and % Coverage: Aluminum/polyester overtape wrapped cable - 100% T.C. braid - 85% min. coverage 36 AWG tinned copper over tape shield Twisted Pair: Left hand lay Applicable Specifications: UL type CL2, CSA PCC FT4 Nominal Diameter 0.415 0.015" - 25 pair cable (See
pinout table)
- 0.460 0.015" - 34 pair cable
(See pinout table) Conductor: 28-7/36 AWG tinned copper .015" nom. dia. Drain Wire: 28-7/36 AWG tinned copper between shields
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Model No. | SQ____ | _____ | _____ |
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Connector Type (male): | | | | | | |
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SCSI-1 (Alt. 2 - A Cable) - Centronics type | 0 | 0 | | |
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DB 50 (non-SCSI standard) | 1 | 1 | | |
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SCSI-2 (Alt. 1 - A Cable) - 50-pin High Density | 2 | 2 | | |
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SCSI-3 (Alt. 3 - P Cable) - 68-pin High Density | 9 | 9 | | |
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SCSI-2 Right Angle (50-pin High-Density, latch fasteners, cable exit pin 1 end) | J | J | | |
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SCSI-2 Right Angle (50-pin High-Density, latch fasteners, cable exit pin 50 end) | K | K | | |
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SCSI-3 Right Angle (68-pin High-Density, Jackscrew fasteners, cable exit pin 1 end) | N | N | | |
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SCSI-3 Right Angle (68-pin High-Density, Jackscrew fasteners, cable exit pin 68 end) | P | P | | |
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VHDCI (68-pin very High-Density, Jackscrew fasteners, cable exit offset) | V | V | | |
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Connector#1---------------------------- | ----| | | | | | Connector#2------------------------------ | ----------- | ---| | | | Length in Feet ------------------------------------------ | ----------- | --------- | 001-160 |
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- Example: Part No. SQ02 - 015: Paralan SCSI Quiet Cable with SCSI-1 (Alt. 2-A, centronics type) connector on one end and SCSI-2 50-pin High Density (Alt. 1 - A) connector on the other, 15 feet long.
Model No. | SQ___ | _____- | M____ |
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Connector Type (male): | | | | | | |
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SCSI-1 (Alt. 2 - A Cable) - Centronics type | 0 | 0 | | |
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DB 50 (non-SCSI standard) | 1 | 1 | | |
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SCSI-2 (Alt. 1 - A Cable) - 50-pin High Density | 2 | 2 | | |
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SCSI-3 (Alt. 3 - P Cable) - 68-pin High Density | 9 | 9 | | |
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SCSI-2 Right Angle (50-pin High-Density, latch fasteners, cable exit pin 1 end) | J | J | | |
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SCSI-2 Right Angle (50-pin High-Density, latch fasteners, cable exit pin 50 end) | K | K | | |
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SCSI-3 Right Angle (68-pin High-Density, Jackscrew fasteners, cable exit pin 1 end) | N | N | | |
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SCSI-3 Right Angle (68-pin High-Density, Jackscrew fasteners, cable exit pin 68 end) | P | P | | |
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VHDCI (68-pin very High-Density, Jackscrew fasteners, cable exit offset) | V | V | | |
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Connector #1------------------------------ | ----| | | | | | Connector#2------------------------------- | --------- | ----| | | | Length in Meters-------------------------------------------- | --------- | --------- | 0.5-50 |
- Example: Part No. SQ09 - M12: Paralan SCSI Quiet Cable with SCSI-1 (Alt. 2 - A cable) connector on one end and SCSI-3 (Alt. 3 - P cable) connector on the other, 12 m long.
This 50-contact, centronics-type, ribbon contact connector is used for Slow, Fast or Ultra, 8-bit Narrow SCSI applications. Frequently called the "SCSI-1 Connector". The SCSI spec terms it the "Alternative 2, A-cable connector". | | 0 | This DB-50 pin-and-socket connector is not recognized by the SCSI specifications. Used on older Sun and DG computers for 8-bit Narrow SCSI applications. | | 1 | Known as the 50-pin high-density SCSI connector. This pin-and-socket connector is also called the "SCSI-2 Connector". The SCSI recognized version has "latch" type fasteners. Used for 8-bit Narrow SCSI devices. The SCSI spec terms it the "Alt 1, A-cable connector". | | 2 | This pin-and-socket DB25 connector was used on Apple computers, devices directed at the Apple market and some older Sun workstations. Not recognized by the SCSI specs. SCSI systems with this connector must be limited to Slow data rates and be no more than 4 or 5 feet long. | | 3 | Known as the 68-pin high-density SCSI connector. This pin-and-socket connector is also called the "SCSI-3 Connector". The SCSI recognized version has "thumbscrew" fasteners. A few SCSI devices have used the "latch" version. Used for 16-bit Wide SCSI devices. The SCSI spec terms it the "Alt 3, P-cable connector". | | 9 | This 68-contact, ribbon type connector is known as the "VHDCI" SCSI connector. Its very small size allows fitting up to 4 of them on the mounting bracket on the back of a PCI or ISA bus card. The SCSI spec terms it the "Alt 4, P-cable connector". | | V | All drawings are views of the female connector -- the one that is normally mounted on the SCSI device. These drawings are not to scale, but their relative sizes are approximately correct. | 50-pin High-Density Right Angle Connector (male) with Latch Fasteners | | J (Cable exit pin 1 end) K (Cable exit pin 50 end) | 68-pin High-Density Right Angle Connector (male) with Jackscrew Fasteners | | N (Cable exit pin 1 end) P (Cable exit pin 68 end) |
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