Communications With The Host; What Is An Nt Link; Connecting To A Temperature Controller - Omron NP Series User Manual

Communications with the Host

1-2 Communications with the Host
1-2-1

What is an NT Link?

1-2-2 Host Link
1-2-3

Connecting to a Temperature Controller

4
NP-series PTs allow the user to allocate words and bits in any PLC area for
use in accessing the required display contents and storing input data.
Operations that can be performed include reading and writing allocated word
contents and bit status directly, changing the display status of objects on the
PT screen, and controlling and providing notification of the PT status.
The NP-series PTs also enable communications with more than one PLC. A
host name is registered for each PLC connected, allowing access to any PLC
areas by specifying the host name and address.
NP-Series PT
When using NP-series PTs, the host can be connected using any of the fol-
lowing methods.
• 1:1 NT Link
• 1:N NT Link (normal or high-speed)
• Host Link
An NT Link is a method for high-speed communications between an OMRON
PLC and an OMRON Programmable Terminal (PT) using a special protocol.
One NP-series PT can be connected to each host. More than one NP-series
PT cannot be connected to the same host. Also, if an NP-series PT is con-
nected, then a PT that supports 1:N NT Links and PLC slaves that support
Serial PLC Links cannot be connected.
NP-series PTs can be connected to a host using either the 1:1 NT Link proto-
col or the 1:N NT Link protocol.
CS/CJ-series and CP-series PLCs can also be connected using high-speed
1:N NT Link communications. For details on the PLCs that support high-
speed 1:N NT Link communications, refer to Appendix E Standard Models .
In the rest of this manual, "NT Link" refers to NT Link communications in gen-
eral, "1:1 NT Link" refers to an NT Link in a 1:1 configuration only, and "1:N NT
Links" refers to NT Links in a 1:N configuration only. Where necessary, "nor-
mal 1:N NT Links" and "high-speed 1:N NT Links" are used. When "1:N NT
Links" is used alone, it refers to both normal and high-speed communications.
Host Link is a serial communications protocol for connecting an OMRON PT
1:1 to an OMRON host (a PLC) to read and write bits and words from the
host. Host Link communications connect a PT to many different PLCs.
OMRON EJ1 Modular Temperature Controllers can be connected with an RS-
485 connection.
Use serial port COM2.
PLC
DM Area I/O Area
Timers/counters
Auxiliary Area
Section 1-2