Omron NT21 - SETUP MANUAL 10-2001 Setup Manual page 92

Connecting to the Host's RS-422A/485 Port
Terminal resistance switch (TERM)
Set to ON (Terminal resistance is present.)
Communications mode switch (WIRE)
For RS-422A: 4 (4-wire)
For RS-485: 2 (2-wire)
Reference:
communications and set the terminator switch to enable or disable the terminat-
ing resistance.
Allocated DM Area Settings for CPU Unit
Settings are written from the Programming Device (a Programming Console or
CX-Programmer) directly into the allocated DM Area settings (PC Setup) of the
CPU Unit. After settings are written, they become effective by turning the power
ON, restarting the Unit, restarting the communication port, or executing the
STUP instruction.
The following table shows the words allocated in the DM Area and the settings.
Allocated DM
word
Writing Value Writing Value
Port 1
DM32000 8200
DM32001 0000 to 0009
DM32006 000j
*1 Set any value between 0000 and 0009 Hex for the communications baud rate.
The same baud rate will be used regardless of the value as long as it is between
0000 and 0009 Hex.
For example, when connecting PTs with model numbers 3, 4, 5, and 6 to port 1,
set DM 32000 to 8200 Hex, DM 32001 to 0000 Hex, and DM 32006 to 0006 Hex.
C-series C200HX/HG/HE(-Z)E and CQM1H
PC Setup Settings
Write the communication conditions directly into the PC Setup (data memory)
using a Programming Device (e.g., CX-Programmer).
Make the setting indicated in the word shown below.
Host Model
Port A of a C200HX/
DM6555
*1
HG/HE(-Z)E
*2
Port 2 of a CQM1H DM6550
*1 The Serial Communications Board's RS-422A/485 port
*2 The Serial Communications Board's RS-422A/485 port
*3 When using C200HE(-Z)E, the maximum PT unit number is 3.
For details on setting the PC Setup settings, refer to the PC's operation manual.
S There are no Serial Communications Boards for the C200HX/HG/HE(-Z)E in
which port B is the RS-422A/485 port.
S There are no Serial Communications Boards for the CQM1H in which port 1 is
the RS-422A/485 port.
Setting the DIP Switches on a C200HX/HG/HE(-Z)E Serial Communica-
tions Board
Set the switches on a C200HX/HG/HE(-Z)E Serial Communications Board as
follows.
Unit number switch
Set the a unique unit number between
0 and F so that there is not a conflict
with the numbers used in other Units.
1:N NT Link mode
(*1)
Communications baud rate (standard)
j = The largest model number of the con-
nected PTs (0 to 7)
Word Writing Value
Use 1:N NT Link
5j00
j j = largest unit number of the
connected PTs (1 to 7)
5j00
Section 5-1
Settings Settings
Setting
a gest u t u be o t e
*3 *3
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