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:

24 AWG stranded (7x32) TC conductors, polyethylene insulation, twisted pairs, overall Beldfoil. (100% coverage) + TC braid shield (90% coverage), 24 AWG stranded TC drain wire, PVC jacket

 

Physical Characteristics (Overall)

Conductor

AWG:

# Pairs           AWG           Stranding           Conductor Material

2                    24                7x32                  TC - Tinned Copper

Total Number of Conductors:                      4

 

Insulation

Insulation Material:

Insulation Material            Wall Thickness (in.)

PE - Polyethylene             0.022

 

Outer Shield

Outer Shield Material:

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

1                 Beldfoil.                                     Tape           Aluminum Foil-Polyester Tape          100

2                                                                   Braid          TC - Tinned Copper                           90

Outer Shield Drain Wire AWG:

AWG          Stranding               Drain Wire Conductor Material

24               7x32                      TC - Tinned Copper

 

Outer Jacket

Outer Jacket Material:

Outer Jacket Material                     Nom. Wall Thickness (in.)

PVC - Polyvinyl Chloride                 0.035

 

Overall Cable

Overall Nominal Diameter:             0.340 in.

 

Pair

Pair Color Code Chart:

Number       Color

1                  White/Blue & Blue/White

2                  White/Orange & Orange/White

 

Mechanical Characteristics (Overall)

Operating Temperature Range:                     -30°C To +80°C

UL Temperature Rating:                                80°C

Bulk Cable Weight:                                         49 lbs/1000 ft.

Max. Recommended Pulling Tension:            87 lbs.

Min. Bend Radius/Minor Axis:                         3.500 in.

 

Applicable Specifications and Agency Compliance (Overall)

Applicable Standards & Environmental Programs

NEC/(UL) Specification:                                    CM

CEC/C(UL) Specification:                                  CM

AWM Specification:                                           UL Style 2919 (30 V 80°C)

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 Directive 2002/95/EC (RoHS):                     Yes

EU RoHS Compliance Date (mm/dd/yyyy):        01/01/2004

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

 

Plenum/Non-Plenum

Plenum (Y/N):                                                     No

Plenum Number:                                                82842

 

Electrical Characteristics (Overall)

Nom. Characteristic Impedance:

Impedance (Ohm)

120

 

Nom. Capacitance Conductor to Conductor:

Capacitance (pF/ft)

12.8

 

Nom. Capacitance Cond. to Other Conductor & Shield:

Capacitance (pF/ft)

23

 

Nominal Velocity of Propagation:

VP (%)

66

 

Nominal Delay:

Delay (ns/ft)

1.540

 

Nom. Conductor DC Resistance:

DCR @ 20°C (Ohm/1000 ft)

24

 

Nominal Outer Shield DC Resistance:

DCR @ 20°C (Ohm/1000 ft)

2.2

 

Nom. Attenuation:

Attenuation (dB/100 ft.)                Attenuation (MHz)

0.600                                            1

 

Max. Operating Voltage - UL:

Voltage

300 V RMS

 

Max. Recommended Current:

Current

2.1 Amps per conductor @ 25°C

 

Put Ups and Colors:

Item #                          Putup              Ship Weight          Color               Notes              Item Desc

9842 060100               100 FT            5.800 LB              CHROME                                2 PR #24 PE SH PVC

9842 0601000             1,000 FT         57.000 LB            CHROME         C                     2 PR #24 PE SH PVC

9842 06010000           10,000 FT       560.000 LB          CHROME                                 2 PR #24 PE SH PVC

9842 060500               500 FT            29.500 LB            CHROME         C                     2 PR #24 PE SH PVC

9842 0605000             5,000 FT         270.000 LB          CHROME                                 2 PR #24 PE SH PVC

Notes:

C = CRATE REEL PUT-UP.