Omron Programmable Terminals NT31 NT31C - Manual (Page 39)

2-1 Section Method for Connection to the Host
28
Communica- Communica-
Usable Communication
Method Communica
tion Type at
PT
Communica
tion Type at
Host
Usable Connection Method
Host
link
NT
Link
(1:1)
NT
Link
(1:N)
Memory
link
Details
1:1 connection via a convertor unit
PT Convertor unit
(NT-AL001)
Host
RS-485
(max. 500 m)
RS-232C
(max. 2 m)
f 88
RS-485
RS-232C
1:N connection via a convertor unit
PT Host Convertor unit
(NT-AL001)
RS-485
(total length 500 m)
RS232C
(max. 2 m)
f
92
RS 485
Direct 1:1 connection
PT Host
RS-485 (max. 500 m)
f 121
RS-485
1:N connection
PT Host
RS-485 (total length 500 m)
f 125
f: Connection possible : Connection not possible
• The RS-232C/RS-422A convertor unit (NT-AL001) requires +5 V, 150 mA at
pin 6 of the RS-232C connector. Check the signals of the RS-232C connector
at the host.
• +5 V is not output from serial port B of the NT31/NT31C. When connecting an
NT-AL001 at serial port B, a separate power supply is required for the NT-
AL001.
• The cable of an NT-AL001 cannot be connected or disconnected while the
power is ON. Always connect or disconnect the cable while the power supply
from the RS-232C cable is OFF (while the host power supply is OFF).
• NT link (1:N) connection is possible even when RS-232C is used at the
NT31/NT31C side for communication with the host, but in this case one NT-
AL001 unit is required for each NT31/NT31C. In this case, it is convenient to
use serial port A of the NT31/NT31C. +5 V is not output from serial port B.