NJR-CTB User
’s Guide
17
[Figure 7.1] LAN port
7.3.1.2 MAINTENANCE / LAN communication specification
[Table 7.1] LAN communication
Physical layer
10Base-T (IEEE802.3i) / 100Base-TX (IEEE802.3u) /
1000Base-T (IEEE802.3ab)
Network layer
ARP, IP, ICMP
Transport layer
TCP
Port used for command control
:
1100
Port used for WEB browser control (HTTP)
:
80
Application layer
HTTP
Note:
Up to 8 connections can be used simultaneously for command control.
7.3.1.3 Limit on the number of TCP-IP connections and port overload management
The NJR-CTB
’s maintenance port supports a maximum of eight simultaneous connections (eight logical
ports). To maintain optimal system accessibility, it is advisable to issue
“port-open” and “port-close”
commands before and after command or query strings are issued. This approach enables eight or more
control devices to be effectively interfaced simultaneously and without concern for communication errors. As a
safeguard, the NJR-CTB incorporates a 30-second timeout window for each port. If any port is inactive for
more than 30 seconds, it will be closed automatically.
[Table 7.2] Increasing connections
Your PC software
NJR-CTB
Connecting TCP-IP
→
(Occupying 1 port)
Sending command (@xxx)
→
←
Replying command (@xxx)
Closing TCP-IP
→
(Releasing 1port)
Note:
If no command is sent from the PC side to the NJR-CTB for 30 seconds, the NJR-CTB automatically
disconnects from that device.
data-)
data-)
6
TRX- (Transmitted/Received
data-)
RX- (Received data-)
TRX- (Transmitted/Received
data-)
TX-
(Transmitted data-)
7
TRX+ (Transmitted/Received
data+)
N.C. (No Connection)
TRX+ (Transmitted/Received
data+)
N.C. (No Connection)
8
TRX- (Transmitted/Received
data-)
N.C. (No Connection)
TRX- (Transmitted/Received
data-)
N.C. (No Connection)
