Performance; Diagnostics - WAGO I/O-SYSTEM 750 Manual

148 Fieldbus Communication
10.1.3.6

Performance

EtherCAT
concepts that could not be realized using classical fieldbus systems.
The high performance of EtherCAT
entire protocol processing takes place in the hardware, and is thus independent
of protocol stack runtime, CPU performance, or software implementation.
In addition, the reference data rate is extremely high because data can be
exchanged in the sending as well as in the receiving direction. Actual data rates
of more than 100 Mbit/s (> 90% reference data rate of 2 x 100 Mbit/s) can be
achieved by the full duplex characteristic of 100BASE-TX.
The principle of EtherCAT
and even allows for an expansion to Gigabit Ethernet.
Furthermore, bandwidth utilization is maximized because each individual user
and each individual datum does not require its own frame. This results in
extremely short cycle times ≤ 100 µs. Up to 1486 bytes of process data can be
exchanged in a single Ethernet frame, which corresponds to almost 12,000 digital
inputs and outputs. Only 300 μs are required to transmit such a large quantity of
data.
A power current control of distributed drives can take place using the Ethernet
system in addition to the speed control, among others.
The large bandwidth enables the system to transmit more status information per
datum.
As an example: The update time for 100 servo axles having 8 bytes of input and
output data respectively is only 100 μs. In this time period, all axles are provided
with nominal values and control data and report their actual positions and status.
Using distributed clocks, the axles can be synchronized with a deviation of
significantly less than a microsecond.
For 200 analog input and output data, for example, only 50 μs (at 20 kHz) are
required, and only 30 μs for 1000 distributed digital input and output data.
10.1.3.7

Diagnostics

Diagnostics demonstrates another outstanding strength of using EtherCAT
Disruptions are recognized quickly and precisely, and are clearly localized so that
they can be remedied in an extremely short period of time.
In the start-up procedure, a check is made at the system start as to whether the
actual input module and output module configurations are identical with the
stored set configurations. The same applies for the typology. In addition, the
network can be automatically read by the configuration upload.
If bit errors occur during the transmission, they are reliably recognized by the
evaluation of the CRC checksum.
The quality of each individual transmission section can be individually monitored
in addition to the recognition and localization of break points. Critical network
segments are exactly localized by the automatic evaluation of the corresponding
Manual
Version 1.2.1
750-354/000-001 EtherCAT® Fieldbus Coupler, ID Switch
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network performance is enormous and enables control and regulation
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technology is not linked to 100 Mbit/s, it is scalable
WAGO-I/O-SYSTEM 750
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technologies can be achieved because the
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