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Multi-drive mode – Rockwell Automation 25B PowerFlex 525 Embedded EtherNet/IP Adapter User Manual

Page 84

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84

Rockwell Automation Publication 520COM-UM001B-EN-E - March 2013

Chapter 7

Using Multi-Drive Mode

Multi-Drive Mode Example for Network

Benefits of Multi-drive mode include:

Lower hardware costs. No need to purchase additional communication
adapters for daisy-chained drives.

Reduces the network node count. For example, in Single-drive mode 30
drives would consume 30 nodes. In Multi-drive mode, 30 drives can be
connected in 6 nodes.

Controller can control, monitor, and read/write parameters for all five
drives.

The trade-offs of Multi-drive mode include:

If the PowerFlex 525 with embedded EtherNet/IP adapter is powered
down, then communications with the daisy-chained drives is disrupted
and the drives will take the appropriate communications loss action set in
each drive.

Communications throughput to the daisy-chained drives will be slower
than if each drive was a separate node on EtherNet/IP (Single-drive
mode). This is because the embedded EtherNet/IP adapter must take the
EtherNet/IP data for the other drives and sequentially send the respective
data to each drive over RS-485. The approximate additional throughput
time for Logic Command/Reference to be transmitted and received by
each drive is:

IMPORTANT

For the examples in the chapter, we will use the PowerFlex 525 as a master
drive with four daisy-chained PowerFlex 4M drives.

Drive

Additional Throughput Time
versus Single-Drive Mode

PowerFlex 525

0 ms

PowerFlex 525 plus 1 drive

+24 ms

PowerFlex 525 plus 2 drives

+48 ms

PowerFlex 525 plus 3 drives

+72 ms

PowerFlex 525 plus 4 drives

+96 ms

Esc

Sel

Up to 5 drives per node

EtherNet/IP

Up to four daisy-chained PowerFlex drives
(PowerFlex 4M shown)

RS-485 cable

PowerFlex 525
as master drive

AK-U0-RJ45-TB2P connector with
terminating resistor (120

Ω

)

AK-U0-RJ45-TB2P connector with
terminating resistor (120

Ω

)

AK-U0-RJ45-TB2P