Mitsubishi Electric MELSEC iQ-R Series User Manual page 95

■Precautions for settings
• Set the timer values of the CC-Link IE TSN Plus module so that the following formula is met. When connecting Mitsubishi
products to the line, configure the same settings for both modules.
Response
TCP ULP
monitoring timer
≥
timer value
value
TCP zero window
TCP resend
=
timer value
timer value
• 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.
TCP ULP timer value
on the external device
Monitoring timer value of the application software
on the external device
*1 "n" is the number of TCP segment transmission and is calculated by the following formula.
Message size sent by the CC-Link IE TSN Plus module
n = A value that
Maximum Segment size
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 CC-Link IE TSN Plus module is 1460 bytes or less
• n = 2 when the size of the message sent by the CC-link IE TSN Plus module is less 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 dial-up 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 CC-Link IE TSN Plus module is 536 bytes or less
• n = 2 when the size of the message sent by the CC-Link IE TSN Plus module is greater than 536 bytes and no more than
1072 bytes
• n = 3 when the size of the message sent by the CC-Link IE TSN Plus module is greater than 1072 bytes and no more than
1608 bytes
■Retry count
When a communication failure occurs due to a problem such as noise, change the value so that the number of retries may
increase.
The number of retries is obtained using the following formula. (When using the default values, 3 = 30  10)
• Number of retries = TCP ULP timer value  TCP resend timer value
When not performing the retry process (when setting 0 time), configure the setting so that the following formula is met. (Set
the same value for the timer values.)
• TCP ULP timer value = TCP end timer value = TCP resend timer value
TCP
TCP end
resend
≥ ≥
timer value
timer value
TCP resend timer value on the
>
CC-Link IE TSN Plus module
TCP ULP timer value on the
>
CC-Link IE TSN Plus module
is rounded up to the nearest integer
IP
assembly
>
timer value
*1
× n
8.1 Parameter Settings for CC-Link IE TSN
8 PARAMETER SETTINGS
8
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