Host Types And Settings; 1:N Connection Using The Host's Rs-232C Port - Omron NT21 - SETUP MANUAL 10-2001 Setup Manual

Connecting to the Host's RS-232C Port
PC (Terminated)
NT21
(Not
(Not
terminated)
terminated)
Example of Good Connection
Reference: CS/CJ-series CPU Units cannot be connected with the 1:1 connection NT link

5-2-1 Host Types and Settings

5-2-2 1:N Connection Using the Host's RS-232C Port

Connecting the NT21s to the Link Adapters (RS-232C)
Note One end of the wire must always be connected to the host (PC), and there must
be no branching. Branching will cause problems such as transmission delays
and communications failures.
Relay Terminal Block
Max. 2 m
NT21 NT21 NT21
NT21
(Terminated)
(Not
terminated)
method. Use the 1:N connection NT Link method (standard or high-speed)
instead of making the 1:1 connection. For details, refer to Using the 1:N NT Link
method (page 55) or Using the High-speed 1:N NT Link method (page 60).
The usage conditions are the same as they are when both the PT and host are
connected through their RS-232C ports.
Refer to the pages listed below for details on the various connection methods,
the hosts that can be connected with each method, and the required host set-
tings.
Method
Host Link
1:1 NT link
1:N NT link
High-speed 1:N NT link
Memory link
This section explains how to connect several NT21 PTs through their RS-232C
ports to a single host through its RS-232C port using Link Adapters and
RS-422A/485 cable. Link Adapters (NT-AL001 or NS-AL002) are required to
convert communication methods between the RS-232C and RS-422A/485 for-
mats.
The following diagram shows a 1:N connection between the RS-232C ports on
several PTs and the RS-232C port on the host through Link Adapters and
RS-422A or RS-485 cable. NT-AL001, NS-AL002 Link Adapters are required to
convert communication methods between RS-232C and RS-422A/485.
PC
NT21 NT21 NT21
Examples of Bad Connections
Using the Host Link Method (page 40)
Using the 1:1 NT Link method (page 51)
Using the 1:N NT Link Method (page 55)
Using the High-speed 1:N NT Link Method (page 60)
Memory Link Method (page 63)
NT-AL001 or
NT21
NS-AL002 NT-AL001
RS-232C cable
(2 m max.)
Section
PC
Relay Terminal Block
NT21 NT21
Reference
Host
5-2
95