User Manual
Appendix A
GFK-1503F
Jan 2020
Performance Data
292
A-5
Ethernet Global Data Sweep Impact
Depending on the relationship between the CPU sweep time and Ethernet Global Data
(EGD) exchange’s period, the exchange data may be transferred every sweep or periodically
after some number of sweeps. Therefore, the sweep impact will vary based on the number
of exchanges that are scheduled to be transferred during the sweep. However, at some
point during the operation of the PLC, all of the exchanges will be scheduled to transfer data
during the same sweep. Therefore, all exchanges must be considered when computing the
worst case sweep impact.
The Ethernet Global Data (EGD) sweep impact has two parts, Consumption Scan and
Production Scan:
EGD Sweep Impact = Consumption Scan Time + Production Scan Time
Where the Consumption and Production Scans consist of two parts, exchange overhead and
byte transfer time:
Scan Time = Exchange Ov Byte Transfer Time
A-5.1
Exchange Overhead
Exchange overhead includes the setup time for each exchange that will be transferred
during the sweep. This overhead varies depending on whether the exchange is consumed
or produced and if the time-stamp for the exchange originates from the PLC itself or from a
remote Network Time Protocol (NTP) server. When computing the sweep impact, include
overhead time for each exchange.
*NTP time synchronization feature is supported IC200CPUE05-HK and previous
versions only.
Consumed Exchange
Produced Exchange
Exchange Overhead*
80
110 (304**)
* Times are in microseconds.
** Represents overhead if the exchange is time-stamped with the PLC clock instead of a
remote NTP server.
A-5.2
Byte Transfer Time
This is the time required to transfer data between the PLC CPU module and the Ethernet
module. The byte transfer time is slightly greater if the PLC memory being written to could
contain overrides due to additional overhead. The times shown in the following table
represent the time to transfer one data byte.
Consumed Exchange
Produced Exchange
Byte Transfer Time*
1 (3.6**)
1
* Times are in microseconds.
** Represents transfer time if memory type supports overrides.