Table of Contents
Advertisement
Chapter 6
ESTABLISHING A DeviceNet COMMUNICATIONS LINK
This chapter guides you to establish a DeviceNet communications link in I/O Message transmission between the
DeviceNet master and the inverter (slave).
I/O Message is a communication process that cyclically transfers data between the DeviceNet master and
slave. For details about I/O Message, refer to Chapter 7 "I/O MESSAGE."
(1) Configure the inverter's function codes described in Chapter 5.
- Set the I/O assembly instances with the inverter's function codes o31 and o32. It is not necessary to set
the same type of I/O assembly instances to input and output.
- Configure the inverter's function codes o27 and o28 with your need. If the instances for user defined
assemblies have been set, configure the function codes o40 to o43 and o48 to o51.
- After completion of the settings above, turn OFF the inverter and the communications card in order to
validate the settings.
For details about the inverter's function codes o31, o32, o40 to o43, and o48 to o51, refer to Chapter 7
"I/O MESSAGE."
(2) Set up the DeviceNet master (PLC, PC tool, or Configurator).
- Set a unique MAC ID (node address), so that it does not coincide with any other nodes.
- Set the baud rate. Make sure that all the nodes have the same baud rate.
- If necessary, install the EDS file of the communications card to the setup tool of the master.
- Allocate an I/O area corresponding to the I/O assembly instance set for the communications card. The I/O
area is either 2 words or 4 words in length.
- Specify the I/O connection type--"Poll" and "Change of State." Specify the communications scan cycle if
necessary.
The communications scan cycle to the communications card should be 10 ms or longer. If a single
inverter is connected to a master, the cycle should be 10 ms or longer; if two inverters are
connected, 5 ms or longer. To minimize the data conflicts and maximize the system reliability, the
cycle of 20 ms or longer is recommended.
The Electric Data Sheet (EDS) file defines parameters on the inverter. Using it quickly accesses
the desired parameters. For the communications card, the file makes it easier to access the
inverter's function codes. For how to obtain the EDS file, refer to Section 1.1 "Acceptance
Inspection."
For details about the setup procedure of the DeviceNet master, refer to the user's manual of the
corresponding master.
(3) Configure the node address and baud rate with the DIP switch on the communications card.
- Before accessing the DIP switch, make sure that both the inverter and the communications card are
turned OFF.
- Set a unique node address, so that it does not coincide with any other nodes.
- Set the same baud rate as the master.
For details about setting the DIP switch, refer to Section 2.2 "DIP Switch."
(4) Have an I/O connection request issued from the DeviceNet master.
- Turn ON the inverter and the communications card.
- Have an I/O connection request issued from the DeviceNet master.
For details about issuing I/O connection requests from the master, refer to the user's manual of the
connected master device. In many PLCs, an I/O connection request is automatically issued at the time
of powering ON.
(5) Start I/O Message.
If both the master and the communications card have been set correctly and the wiring is proper, I/O
message connection will be established in response to the connection request and data transmission starts.
At this stage, the MS and NS LEDs on the communications card light in green. It is ready to control the
inverter according to the specified I/O assembly instances.
15
Advertisement
Table of Contents
