Omron NT11 - 01-2004, User Manual

Page: 51 / 186

38
Connection to a PLC by the Host Link (RS-422A Type)
Section 2-5
The following table shows the words allocated in the DM Area and the set-
tings.
2-5 Connection to a PLC by the Host Link (RS-422A Type)
Connect the NT11 to an OMRON PLC by using the RS-422A type host link
method.
If the distance between the NT11 and the PLC is greater than 15 m, this
method should be used. The maximum distance over which a connection can
be made is 500 m.
when using the RS-422A method, the host computer and PLC are usually
connected in a 1 to N ratio (more than one PLC), but in the special case of the
connection between the NT11 and PLC, the ratio is 1 to 1.
In order to make a connection to the PLC using the host link method (RS-
422A type), the “Comm. Type” memory switch of the NT11 must be set to the
host link, and the “Comm. Port” memory switch must be set to RS-422A. For
details on memory switch settings, refer to
3-7-1 Selecting the Host Commu-
nication Method (page 73).
2-5-1 Compatible PLCs
When Using the Host Link Method
Compatible Host Units
Some models and series of OMRON PLCs have the RS-422A type Host Link
function built in. With a CS series, CJ series, and CQM1H Board or Unit, and
CQM1H, the Host Link method can be used by installing a Serial Communica-
tions Board. In addition, some C200HX/HG/HE(-Z)E devices have an integral
CPU Unit that can be connected in the Host Link method by installing a Serial
Communications Board.
With the CPM2A and CPM2C, an RS-422A type of 1:1 NT Link can be con-
nected through a CPM1-CIF11 RS-422A Adapter.
Check the model and series of the PLC and the type of the installed Board or
Unit before making a connection.
Allocated DM word Value Settings
Port 1 Port 2
DM32000 DM32010 8000 Host Link mode, 2 stop bits, even parity, data
length 7 bits
DM32001 DM32011 0000 Baud rate 9,600 bps.
0007 Baud rate 19,200 bps.
0008 Baud rate: 38,400 bps.
0009 Baud rate: 57,600 bps.
000A Baud rate: 115,200 bps.
DM32002 DM32012 0000 Transmit delay time 0 ms.
DM32003 DM32013 0000 No CTS control Unit No. 0 for Host Link