RS-485的接口信号电平比RS-232-C降低了，就不易损坏接口电路的芯片， 且该电平与TTL电平兼容，可方便与TTL 电路连接。
        RS-485的数据最高传输速率为10Mbps。RS-485接口是采用平衡驱动器和差分接收器的组合，抗共模干扰能力增强，即抗噪声干扰性好。
       RS-485最大的通信距离约为1219M，最大传输速率为10Mb/S，传输速率与传输距离成反比，在100Kb/S的传输速率下，才可以达到最大的通信距离，如果需传输更长的距离，需要加485中继器。
       RS-485总线一般最大支持32个节点，如果使用特制的485芯片，可以达到128个或者256个节点，最大的可以支持到400个节点。

General Description:

22 AWG stranded (7x30) tinned copper conductors, Datalene. insulation, twisted pairs, overall Beldfoil. shield (100% coverage) plus a tinned copper braid (65% coverage), drain wire, UV resistant PVC jacket.

 

Physical Characteristics (Overall)

Conductor

AWG:

# Pairs    AWG    Stranding    Conductor Material      Dia. (in.)

1             22         7x30           TC - Tinned Copper    .030

Total Number of Conductors:                                         2

 

Insulation

Insulation Material:

Insulation Trade Name      Insulation Material

Datalene.                           FHDPE - Foam High Density Polyethylene

 

Outer Shield

Outer Shield Material:

Layer #    Outer Shield Trade Name   Type    Outer Shield Material                  Coverage (%)

1              Beldfoil.                               Tape    Aluminum Foil-Polyester Tape    100.000

2                                                          Braid    TC - Tinned Copper                     65.000

 

Outer Shield Drain Wire AWG:

AWG    Stranding     Drain Wire Conductor Material

22        7x30             TC - Tinned Copper

 

Outer Jacket

Outer Jacket Material:

Outer Jacket Material

PVC - Polyvinyl Chloride

 

Overall Cable

Overall Nominal Diameter:              0.281 in.

 

Pair

Pair Color Code Chart:

Number        Color

1                   White/Blue Stripe and Blue/White Stripe

Pair Lay Length & Direction:

Lay Length (in.)

3.750

 

Mechanical Characteristics (Overall)

Operating Temperature Range:                         -20°C To +60°C

Non-UL Temperature Rating:                             60°C

Bulk Cable Weight:                                             44 lbs/1000 ft.

Max. Recommended Pulling Tension:                60 lbs.

Min. Bend Radius/Minor Axis:                             2.800 in.

 

Applicable Specifications and Agency Compliance (Overall)

Applicable Standards & Environmental Programs

NEC/(UL) Specification:                                         CM, PLTC

CEC/C(UL) Specification:                                       CM

EU Directive 2011/65/EU (ROHS II):                      Yes

EU CE Mark:                                                           Yes

EU Directive 2000/53/EC (ELV):                             Yes

EU Directive 2002/95/EC (RoHS):                          Yes

EU RoHS Compliance Date (mm/dd/yyyy):            10/01/2005

EU Directive 2002/96/EC (WEEE):                         Yes

EU Directive 2003/11/EC (BFR):                            Yes

CA Prop 65 (CJ for Wire & Cable):                         Yes

MII Order #39 (China RoHS):                                 Yes

 

Flame Test

UL Flame Test:                                 UL1685 UL Loading

CSA Flame Test:                               FT1

 

Suitability

Sunlight Resistance:                          Yes

 

Plenum/Non-Plenum

Plenum (Y/N):                                    No

Electrical Characteristics (Overall)

Nom. Characteristic Impedance:

Impedance (Ohm)

120

 

Nom. Capacitance Conductor to Conductor:

Capacitance (pF/ft)

11.0

 

Nom. Capacitance Cond. to Other Conductor & Shield:

Capacitance (pF/ft)

20.9

 

Nominal Velocity of Propagation:

VP (%)

78

 

Nom. Conductor DC Resistance:

DCR @ 20°C (Ohm/1000 ft)

14.7

 

Nominal Outer Shield DC Resistance:

DCR @ 20°C (Ohm/1000 ft)

2.8

 

Nom. Attenuation:

Description  Freq. (MHz)  Start Freq. (MHz)  Stop Freq. (MHz)  Attenuation (dB/100 ft.)

                    1                                                                                .5

 

Max. Operating Voltage - UL:

Voltage

300 V RMS (NEC Type PLTC)

300 V RMS (NEC Type CM)

 

Max. Recommended Current:

Current

2.7 Amps per conductor @ 25°C

Other Electrical Characteristic 1:

Input Impedance/Unfitted Impedance .5 - 10 MHZ, 120 +-12 Ohms

 

Notes (Overall)

Notes: Oil Resistance: Passes Oil Res II Per UL1277, Table 10.17. For CPE jacketed version order Part No. YR44345.

 

Put Ups and Colors:

Item #                   Putup         Ship Weight    Color       Notes     Item Desc

3105A 0101000   1,000 FT    46.000 LB       BLACK     C          1 PR #22 FHDPE SH PVC

3105A 010500     500 FT       23.000 LB       BLACK     C          1 PR #22 FHDPE SH PVC

3105A 0105000   5,000 FT    230.000 LB     BLACK     C N       1 PR #22 FHDPE SH PVC

Notes:

C = CRATE REEL PUT-UP.

N = FINAL PUT-UP LENGTH MAY VARY -0% TO +10% FROM LENGTH SHOWN.