Watlow MICRODIN - Manual (Page 13)

EIA-485 Network
The MicroDIN EIA-485 (RS-485) Network Characteristics
An EIA-485 interface uses three wires in a half-duplex configuration.
The EIA-485 standard specifies a T+/R+ line; a T-/R- line; and a common line.
EIA-485 interprets a -5 volt signal <None> as a 1, a +5-volt signal as a 0. Up to
32 remote devices can be connected to a master on a multi-drop network up to
4,000 feet long.
For industrial networks, EIA-485 offers low impedance, a multiple-device
capability, strong noise immunity and the long distance capability.
PC Connection via 232/485 Converter
Watlow recommends connecting the MicroDIN to your personal computers with
an EIA-232 (RS-232) to EIA-485 (RS-485) converter.
The 232-to-485 converters are proven reliable, low cost, and readily available.
We recommend these suppliers:
• B & B Electronics Manufacturing Company
707 Dayton Road, PO Box 1040, Ottawa, IL 61350
Tel: (815) 433-5100; Fax: (815) 434-7094; Web: http://www.bb-elec.com
Request part number: 485OIC with a power supply and the correct 25-pin
gender connector for your computer.
• CMC (Connecticut microComputer, Inc.)
P.O. Box 186, Brookfield, CT 06804
Tel: (800) 426-2872, (203) 740-9890; Fax: (203) 775-4595
Request part number: ADA485L with the correct 25-pin gender connector
for your computer.
See Chapter 3 for wiring details.
Wa t l o w M i c r o D I N 2 . 3
Communications
Setup