5.RS485 SPECIFICATIONS

MIUXXXX/485 are low-power Transceiver for RS485 and RS422 communication

Features:

Point to Point

or Multidrop/Multipolling

 

 

 

 

 

 

Full or Half Duplex

 

 

 

 

 

 

 

Drivers are short - circuit current limited

& protected against excessive

 

power

 

 

 

 

 

 

 

 

dissipation (shutdown will places the drivers in a high - impedance state).

 

When Drivers are disabled (by TXD),

drivers

will switch to

high

impedance

state.

 

 

 

 

 

 

 

 

Note in two-wire or multi-drop/multi-polling networks TX enable by TXD

 

should be active

 

 

 

 

 

 

 

Receiver input impedance is 12K ohms.

 

 

 

 

 

 

Reduced slew- rate drivers that minimize EMI and reduce reflections

caused

by improperly

terminated cables

 

This

will

allow

error -

free

transmitted

data up to 200Kbps

 

 

 

 

 

 

 

RS485/RS422

standard covers line

lengths

up to

4000

feet. For

line

lengths

 

 

 

 

 

 

 

 

 

greater than 4000 feet a line repeater

can be added.

 

 

 

 

MIUXXXX/485 can drive 4000 feet

of 26AWG twisted - pair cable at

 

200k bps into 120 ohms load.

 

 

 

 

 

 

To minimize reflections, the line should be terminated at both ends. In multi - polling/multi - drop environments (up to 32 drops) all drops off

themain cable should be as short as possible.

Only the Master/Host unit and the end of cable unit should be terminated.

Typical Speed versus Distance - (4-wire point to point 26 AWG twisted cable)

 

 

 

 

SPEED

DISTANCE

 

1200bps

6.0 miles(9.6 km)

 

2400 bps

4.5 miles (7.2 km)

 

4800 bps

4.0 miles (5.5 km)

 

9600 bps

2.5 miles (4.0 km)

 

19,200 bps

1.8 miles (2.9 km)

 

38,400 bps

1.4 miles (2.1 km)

 

56,400 bps

1.1 miles (1.8 km)

 

115,000 bps

0.6 miles (0.9 km)

NOTE: Speed and distances will depend on actual operating environment.

6. ENVIRONMENTAL SPECIFICATIONS

The CIU/485 (MIUXXX\485) meets the following environmental specifications.

Install Op and Diags for MIU Modems and RS485 (0049-0002-010A)

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Telenetics MIU Dial or Leased Line modem with RS-485 manual Environmental Specifications, Speed Distance