Omron Programmable Terminals NT31 NT31C Setup Manual page 126

Connecting to the Host's RS-422A/485 Port
Using the High-speed NT Link (1:N) Method
Setting the Front Switches
RDY
COMM1
COMM2
Port 1
RS-232C
OFF ON TERM
2
Port 2
RS-422A/485
SCB41
Allocation DM Area Settings for CPU
Settings are written from the Programming Device (a Programming Console or
CX-Programmer) directly into the allocation DM area (system setting area) of
the CPU. After settings are written, they become effective by turning the power
ON, restarting the unit, restarting the communication port, or executing the
STUP command.
In the following, the channel numbers of the allocation DM area and settings are
shown.
Allocation DM
area (CH)
Writing Value Writing Value
Port 2
DM32010 8200
DM32011 0000 to 0009
DM32016 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 2 in
the NT link (1:N), set a value of 8200 Hex for D32010, 0000 Hex for DM32011,
and 0006 Hex for D32016.
Compatible Host Units
Only OMRON's CS1H and CS1G PCs support the high-speed 1:N NT Link
through RS-422A/RS-485. The high-speed 1:N NT Link must be established
through a CS1W-SCB41-E Serial Communications Board. (If a Serial Commu-
nications Board is used, even CS1-series Units without the "-V1" suffix can be
connected via high-speed 1:N NT Link.)
Be sure to check the model number of the PC and Board/Unit before trying to
establish the high-speed 1:N NT Link.
The following table shows which CS1-series PCs can be connected to an
NT31/NT31C with the high-speed 1:N NT Link through RS-422A/RS-485.
PORT1
Terminal resistance setting switch (TER)
Set to ON (Terminal resistance is present.) (right side)
4 WIRE
Two wire type/four wire type changeover switch (WIRE)
For RS-422A : 4 (4 wire type) (right side)
PORT2
(RS422/
For RS-485 : 2 (2 wire type) (left side)
RS485)
NT link (1:N) mode
(*1)
Communications baud rate (standard)
j = The largest model number of the con-
nected PT (0 – 7)
Section 5-2
Settings Settings
115