Parameter configuration – Rockwell Automation 25B PowerFlex 520-Series Adjustable Frequency AC Drive User Manual User Manual
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Rockwell Automation Publication 520-UM001G-EN-E - September 2014
Appendix C
RS485 (DSI) Protocol
Only pins 4 and 5 on the RJ45 plug should be wired. The other pins on the
PowerFlex 520-series drive’s RJ45 socket must not be connected because they
contain power, etc. for other Rockwell Automation peripheral devices.
Wiring terminations on the master controller will vary depending on the master
controller used and “TxRxD+” and “TxRxD-” are shown for illustration
purposes only. Refer to the master controller’s user manual for network
terminations. Note that there is no standard for the “+” and “-” wires, and
consequently Modbus device manufacturers interpret them differently. If you
have problems with initially establishing communications, try swapping the two
network wires at the master controller.
Standard RS485 wiring practices apply.
•
Termination resistors need to be applied at each end of the network cable.
•
RS485 repeaters may need to be used for long cable runs, or if greater than
32 nodes are needed on the network.
•
Network wiring should be separated from power wires by at least
0.3 meters (1 foot).
•
Network wiring should only cross power wires at a right angle.
I/O Terminal C1 (RJ45 Shield) for the Ethernet and DSI network cables on the
PowerFlex 520-series drive must also be connected to PE ground (there are two
PE terminals on the drive). The shield for the network cables should be
connected to PE ground at one end only.
I/O Terminal C2 (Comm Common) is internally tied to Network Common for
the network signals, and NOT to RJ45 Shield. Tying I/O Terminal C2 to PE
ground may improve noise immunity in some applications.
See I/O Control Terminal Designations on
and
for more
information.
Parameter Configuration
The following PowerFlex 520-series drive parameters are used to configure the
drive to operate on a DSI network.
Configuring Parameters for DSI Network
Parameter
Details
Reference
Set to 3 “Serial/DSI”
if Start is controlled from the network.
[Speed Reference1]
Set to 3 “Serial/DSI” if the Speed Reference is controlled from the network.
[RS485 Data Rate]
Sets the data rate for the RS485 (DSI) Port. All nodes on the network must be
set to the same data rate.
[RS485 Node Addr]
Sets the node address for the drive on the network. Each device on the
network requires a unique node address.
[Comm Loss Action]
Selects the drive’s response to communication problems.
[Comm Loss Time]
Sets the time that the drive will remain in communication loss before the
drive implements
[Comm Loss Action].
[Comm Format]
Sets the transmission mode, data bits, parity and stop bits for the RS485 (DSI)
Port. All nodes on the network must be set to the same setting.
[Comm Write Mode]
Set to 0 “Save” when programming drive.
Set to 1 “RAM only” to only write to volatile memory.