Mitsubishi Q00JCPU User Manual page 522

7
COMMUNICATION
PORTS OF CPU MODULE
(3) Precautions
7
- 8 7.2 GX Developer/GOT Connection
USING
• When the protocol is set to "TCP", existence check using the KeepAlive function
is performed.
The CPU module sends an existence check message five seconds after the last
message from the external device is received and waits to see whether a
response from the external device is received. If there is no response, the CPU
module keeps sending an existence check message in five-second intervals.
When a response has not been confirmed within 45 seconds, the connection is
disconnected, considering that no external device exists.
The connection may be disconnected if the external device does not support the
TCP KeepAlive function (response to ACK messages for KeepAlive).
• Establish connections within the number of protocols set for open settings of PLC
parameter.
If connections are established exceeding the setting range from a personal
computer, the status of some applications may change into the wait status,
making the application inoperable.
• Establish connections within the number of protocols set for open settings of PLC
parameter.
If connections are established exceeding the setting range from a personal
computer, the time period causing a time-out error may increase.
• In TCP connection, if no ACK response message for TCP protocol device is
received from the external device, resend processing is performed. Resend
processing is performed six times, 0.3, 0.6, 1.2, 2.4, 4.8, and 9.6 seconds after
the first message. If there is no ACK response within a period of 19.2 seconds
after the last message is resent, the connection is disconnected, considering that
the external device is not operating normally. (The connection is disconnected
within the total period of 38.1 seconds.)
• To communicate with multiple MELSOFT devices using the UDP protocol, set the
same number of protocols as MELSOFT devices in PLC parameter.
Hub
Personal computer Personal computer
Set the same number
of protocols as MELSOFT
devices.
Figure 7.10 Setting for MELSOFT connection using UDP protocol
BUILT-IN ETHERNET
Ethernet
Personal computer