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Intelligent RS-485 and RS-422 Adaptors

 

RS-485 and RS-422 Cabling 

RS-422 and RS-485 are specifications for multi-drop serial digital 
communications over long distances with high noise immunity. 

In ASP products, RS-422 is a four-wire connection (with one twisted-
pair used for transmission and one twisted-pair used for reception), and 
RS-485 is a two-wire connection (with transmission and reception 
taking place alternately over a single twisted-pair). 

ASP RS-422 products 

ASP RS-485 products 

ASPNet Terminals 

ClassNet Terminal 

ASPNet Access Controller 

ZipNet Terminal 

Networked Portable BCR 

WandNet 

ASP RS-422 and RS-485 networks must be wired using a single run of 
shielded twisted-pair cable, daisy chained to each unit.  The cable must 
be looped to each unit in one continuous run - there must be no "T" or 
"Y" connections in the cable.  Cable joins are acceptable only at the 
actual connectors at each unit (see the diagram below). 

Note that although 
this diagram shows 
ClassNet or ZipNet 
units, the way the 
cable is run is 
applicable to 

all

 

ASP networked 
units. 

In a typical 
installation, one 
end of the cable is 
connected to the 
Intelligent RS-485 
or RS-422 
Adaptors at the 
controlling computer (which plugs into one of the computer's serial 
ports).  The cable is then run to each networked unit in turn, with no 
branches or junctions. 

Summary of Contents for Intelligent RS-422

Page 1: ...rocomputers 14 Business Park Drive Notting Hill Victoria 3168 Australia Telephone 03 9578 7600 FAX 03 9578 7727 email solutions asp com au World Wide Web http www asp com au ASP Microcomputers is a di...

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Page 3: ...S 485 and RS 422 Cabling 2 Cable Termination 3 Power Supplies 4 Network Expansion 5 The Main Cabling Points Again 5 Technical Information 6 RS 232 Connector 6 RS 485 Connector 6 RS 422 Connector 7 RJ...

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Page 5: ...ocol to communicate with to the PC with the PC being the master Because RS 422 uses a separate pair of wires for data in each direction the Intelligent RS 422 adaptor is always able to both send and r...

Page 6: ...minal Networked Portable BCR WandNet ASP RS 422 and RS 485 networks must be wired using a single run of shielded twisted pair cable daisy chained to each unit The cable must be looped to each unit in...

Page 7: ...ch contain two or three twisted pairs of wires respectively are available in 100 metre and 500 metre rolls from A G Garlands Co Pty Ltd in Melbourne phone 03 9543 6411 with offices in other states Oth...

Page 8: ...S cable for RS 485 installations and MCP 3S cable for RS 422 installations provides for a spare pair of wires In some installations it will be possible to use this spare pair to provide power over the...

Page 9: ...erial ports Remember that each section of the network can be up to 1200 metres long and can support up to 31 units Although we have had some users connect more than 31 units together in a single netwo...

Page 10: ...nt to make your own cable Pin Function DB 25 on PC DB 9 on PC 2 Data from PC 2 3 3 Data to PC 3 2 7 Signal Ground 7 5 Note that the Intelligent RS 485 and RS 422 Adaptors use only the transmit and rec...

Page 11: ...Supply ve RJ 45 Connector The Intelligent RS 485 and RS 422 Adaptors also provide for the use of Category 3 or Category 5 twisted pair cable via an RJ 45 socket on the front panel This connector is wi...

Page 12: ...RS 485 adaptor the RS 422 adaptor uses the same physical PCB but with different components fitted Jumper 1 if fitted connects unregulated DC voltage from the plug pack powering the Adaptor to the RS 4...

Page 13: ...will be paid by ASP in the case of warranty repairs ASP welcomes suggestions for improvements to our products and documentation Year 2000 Statement The Intelligent RS 485 and RS 422 Adaptors are hard...

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