Appendix I - Multidrop Communications; Figure A-6 Typical Multidrop Network - Microscan MS-3000 User Manual

Appendix I — Multidrop Communications
This appendix describes the rules for setting up a concentrator or controller to com-
municate with a decoder in standard Multidrop protocol, as presented in
col," on page 2-6.
Figure A-6 shows a typical Multidrop
network in which 1 to 50 scanners
can communicate with a host via an
intermediary device, a concentrator
or a controller.
Multidrop Addresses
• No two decoder in the Multidrop
Network can have the same
address.
• Each decoder in the network must
have an address (from 01 to 50)
assigned in its configuration pro-
gram.
Each address has its own separate
poll and select address (from 1C to
7F hex as shown in table A-6 on page
For example, during a polling sequence, decoder 03 expects a 20 hex ("SP"
ASCII poll character) from the concentrator. And during a select command, it
looks for a select value 21 hex ("!" ASCII select character).
MS-3000 Single Head Decoder User's Manual
Multidrop Communications
"Proto-
Host
Concentrator
or Controller Polled Protocol
Multidrop ONLY
RS-485 Interface
(LAN)
Decoder 01
Decoder 02
Decoder 03

Figure A-6 Typical Multidrop Network

A-20).
A-17