Mitsubishi Electric MELSEC iQ-R02CPU - Precautions for Settings; Setting Value for each Timer of the External Device Side

2 PARAMETER SETTINGS
2.3 Application Settings
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2
Precautions for settings
■Setting value for each timer of the Ethernet-equipped module side.
Set the timer values so that the following formula is met.
When connecting Mitsubishi products to the line, configure the same settings for both modules.
■Setting value for each timer of the external device side.
Set the timer values so that the following formula is met. The frequency of a communication error, such as a transmission
timeout, may be higher if the timer values do not meet the formula.
*1 "n" is the number of TCP segment transmission and is calculated by the following formula.
Ex.
The number of TCP segment transmission when communications are performed on the same line
The Maximum Segment Size is 1460 bytes on the same line (without a router) and the number of TCP segment transmissions
is as follows.
• n = 1 when the size of the message sent by the Ethernet-equipped module is 1460 bytes or less
• n = 2 when the size of the message sent by the Ethernet-equipped module is greater than 1460 bytes
Ex.
The number of TCP segment transmission when communications are performed on a different line
The Maximum Segment Size is at least 536 bytes on another line (via a dialup router or other communication device) and the
number of TCP segment transmissions is as follows.
• n = 1 when the size of the message sent by the Ethernet-equipped module is 536 bytes or less
• n = 2 when the size of the message sent by the Ethernet-equipped module is greater than 536 bytes and no more than
1072 bytes
• n = 3 when the size of the message sent by the Ethernet-equipped module is greater than 1072 bytes and no more than
1608 bytes
≥≥≥>
Response
monitoring timer
value
TCP ULP
timer value
TCP end
timer value
TCP
resend
timer value
IP
assembly
timer value
=
TCP resend
timer value
TCP zero window
timer value
>
>
× n
*1
TCP ULP timer
value on the external
device
TCP resend timer value
on the Ethernet-equipped
module
Monitoring timer value of the
application software on the external
device
TCP ULP timer value on
the Ethernet-equipped
module
Message size sent by the Ethernet-equipped module
Maximum Segment size
n = A value that is rounded up to the nearest integer