Chapter 2
Multidrop Communications
2-2
MS-5000 Multidrop Concentrator User’s Manual
2-
M
ul
tidro
p Comm
.
Standard Single Concentrator Network
In a typical multidrop network (figure
2-1), the host communicates with the
concentrator in a point-to-point
(unpolled) protocol. The concentrator
communicates with decoders and
other devices in Multidrop.
1
Each
decoder must be individually config-
ured to Multidrop and assigned a
unique address (from 01 to 50).
Note:
The MS-5000 concentrator is
programmed to communicate with
decoders in Multidrop protocol only;
therefore, User Defined Multidrop can-
not be used when setting up decoders.
Multidrop Addresses
Rules
:
1. Each device must have an
address assigned in its configuration menu.
2. No two devices can have the same address.
3. Additional devices (up to 50) can be added at any time to an active
system (see “Polling Cycle Timing” on page 2-7).
In a multidrop network, each device is assigned a number from 01 to 50.
However, during poll and select sequences the concentrator provides back-
ground substitution from a table of hexadecimal ASCII values associated with
each address (see table A-1 on page A-3).
For example, when transmitting a poll request to a decoder the concentrator
uses the poll value 20 hex (“SP” ASCII poll character).
When the concentrator relays a
select
command from the host to the same de-
vice, it uses the select value 21 hex (“!” ASCII select character). This allows a
device to readily distinguish between a poll and select sequence.
Data to the Host
Data that is transmitted to the host (bar codes, noreads, counters, etc.) from
multidrop devices is handled by
poll
requests.
1. See Chapter 2, “
” for more details on Multidrop and other protocols, and
“Multiple Concentrator Network” on page 2-8.
Host
Series
Concentrator
Decoder 01
Decoder 02
Decoder 03
5000
Multidrop ONLY
RS-485 Interface
Unpolled Protocol
RS-232 or RS-422
Interface
(LAN)
Figure 2-1 Typical Multidrop Network
Polled Protocol
Summary of Contents for MS-5000
Page 1: ...MS 5000 Multidrop Concentrator User s Manual P N 83 005000 REV J...
Page 8: ...viii MS 5000 Multidrop Concentrator User s Manual...
Page 52: ...Chapter 3 Menu Configuration 3 18 MS 5000 Multidrop Concentrator User s Manual 3 Serial Config...
Page 66: ...Chapter 4 Serial Commands 4 14 MS 5000 Multidrop Concentrator User s Manual 4 Operations...
Page 90: ...A 14 MS 5000 Multidrop Concentrator User s Manual Appendices...
