
1 Introduction
1-10
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
1-5
System Configurations
This section explains the system configuration supported by each serial communications mode.
*1
The maximum cable length for RS-232C is 15 m. The RS-232C specification does not define any use over 19.2
Kbps. Refer to the manual for the device being connected.
*2
The maximum total cable length for RS-422/485 is 500 m when an NT-AL001 Link Adapter is used. The length
includes branch lines. Communications distance may vary by the device being connected. Refer to the manual
for the device.
*3
The maximum length is restricted to 2 m when an NT-AL001 Link Adapter is connected.
1-5-1
Protocol Macro, Serial Gateway, No-protocol, or Modbus-RTU
Slave
PLC:
General-
purpose
external
device
Connection configuration
Required
devices
Connected
serial
communica-
tions
port/Remarks
1:1
Port:
RS-232C
CJ1W-SCU22
Port 1 or 2
CJ1W-SCU44
Port 2
NT-AL001 Con-
verting Link
Adapter
Converts
between RS-
232C and
RS-422A/485
5-V power sup-
ply
For NT-AL001
Link Adapter
Connection of a Serial Communications Unit to a device with an
RS-232C or RS-422A/485 port.
RS-232C
RS-232C
interface
NT-AL001
RS-232C
RS-422A/485
Resistance ON
NT-AL001
Resistance ON
5-V power
RS-232C
interface
NT-AL001
RS-232C
RS-422A/485
Resistance ON
RS-422A/485
interface
*2
*3
*2
*3
*1
Resistance
ON