PowerFlex 4 40 with MicroLogix1100 on ModbusRTU broadcast Distribution Related to Open Inverter Use Rockwell Offices Options Use Drives Team Application Experience (Name) only Page 1 of 6 Generated by.
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Overall Description PowerFlex class drives can be controlled over Modbus RTU using the built-in serial interface (DSI connector) on the drive This application note details the Micrologix 1100 plc being used as Modbus RTU master to control PowerFlex class drives using broadcast control To control a drive on Modbus RTU, each drive needs to use a seperate message (MSG) command for the Logic Control word, Speed Reference word, Logic Status word and Speed Feedback word With a large number of drives on the network, it can take a significant period of time before the MSG instruction for the last drive to start, is executed Modbus RTU supports a global broadcast feature, whereby one MSG instruction is used to write the same value to same register in every drive, by using the Modbus RTU command ‘16’ to the Modbus address ‘0’ This means that we could broadcast the Logic Command word to start /stop all the drives together, or provide a common speed reference to the drives This could significantly reduce the time to control a number of drives on the network The MicroLogix 1100 has an embedded multi functional LCD for on-line editing, and EtherNet/IP for connecting to an peer to peer network or our programming PC The PowerFlex drives being used in this test are a PowerFlex4 setup as Node 1, and a PowerFlex4M setup as Node Distribution: x Open Rockwell Offices Drives Team Related to: x Inverter Use Options Use Application Experience _(Name) only Page of Generated by Date Revision D.J.Withenshaw 05/09/2007 A Equipment used for test MicroLogix 1100 1763-L16AWA RSLogix500 CPR ver and RSLinx ver 2.51 The PowerFlex class drives need a minimum firmware revison to support Modbus RTU code ‘16’: PowerFlex – frn 4.02 PowerFlex4M – frn 1.01 PowerFlex40 – frn 3.03 PowerFlex40P and 400 have not been tested 1761-CBL-PM02 ser B, PC to MicroLogix programming cable 1763-NC01 The phoenix plug pin connectons are the same as the RS485 on the NET-AIC AK-U0-RJ45-TB2P position terminal block Modbus RTU requires a 120 Ohm terminator at each end of the network Putting a link between pins & of the terminal block terminates one end, and a 120 Ohm resistor is screwed into the position terminal block at the other end Drive Parameter setup Drive parameters need to be setup as below When para change complete, cycle the drive power Parameter PF4, 40, 40P, 400 P36 P38 A103 A104 A107 Parameter PF4M P106 P108 C302 C303 C306 Details Value Start source from Network Speed reference from network Comm data rate set at 19200kb Comm node address set to Comm format set to RTU 8-N-1 5 1&2 MicroLogix Setup The MicroLogix 1100 needs to be setup first using the serial cable 1761-CBL-PM02 on channel If when connecting to the ML1100 an error is reported that it is not an SLC, then upgrade RSLogix to ver and RSLinx to ver 2.50 Startup RSLogix500 and create a new project with the Micrologix 1100 Distribution: x Open Rockwell Offices Drives Team Related to: x Inverter Use Options Use Application Experience _(Name) only Page of Generated by Date Revision D.J.Withenshaw 05/09/2007 A Select channel configuration Setup Channel EtherNet IP address and subnet Make sure you uncheck the BootP enable, and then download to the controller To make the IP address stick, cycle the power on the ML1100 Now we have the IP address in the ML1100, then we can reconfigure our computer and go-line using the EtherNet connection This will allow us to remove the serial cable 1761-CBL-PM02 on channel 0, and use plug in the 1763-NC01 and reconfigure Channel for Modbus RTU Additionally ensure that the settings within the ML1100 are setup on the LCD: ESC … Scroll down … Advance Set …… DCOMM Cfg = disable Change to cable 1763-NC01, and select the channel configuration as before Setup channel to be Modbus RTU master at 19200 with no parity Distribution: x Open Rockwell Offices Drives Team Related to: x Inverter Use Options Use Application Experience _(Name) only Page of Generated by Date Revision D.J.Withenshaw 05/09/2007 A Make sure you adjust the protocol control from the default No handshaking to No handshaking (485 network) and the timeouts /delays to 20ms Download configuration to controller using the EtherNet connection Once the ML1100 is in run mode, both COMM0 and COMM1 will be flashing fast The ML1100 communicates with the drive using MSG instructions on Modbus RTU So we create a number of MSG instructions for the Logic control, reference , logic status and drive speed feedback The MSG instructions are cascaded so that they all operate in sequence This scheduling of MSG instructions is necessary to ensure that each instruction receives its hand-shake and completes properly Distribution: x Open Rockwell Offices Drives Team Related to: x Inverter Use Options Use Application Experience _(Name) only Page of Generated by Date Revision D.J.Withenshaw 05/09/2007 A The logic command data will be stored in N15:0, so configure the message to send N15:0 to the Modbus address for the logic command at 8192 (this means modbus sends to address 8193) Notice that we use the command ’16 Write Multiple Registers’, and the Slave node address is ‘0’ When the program is downloaded, we can go online and change the logic word to start and stop the drive Double click on the N15 data file, and change the value of N15:0 to The drives will now start Changing the value of N15:0 to will stop the drives The bits that are part of the Logic Control word are: Distribution: x Open Rockwell Offices Drives Team Related to: x Inverter Use Options Use Application Experience _(Name) only Page of Generated by Date Revision D.J.Withenshaw 05/09/2007 A The plc MSG 11:1 broadcasts the reference to all drives on address 8194 via N15:1 Therefore change the value of N15:1 between to 500 = 50.0Hz The broadcast message is a write MSG to all the drives on the network, typically used for the Logic Control and reference words Other drive registers would be read with a single MSG ’03 Read Holding Register’ command The most important registers are: Address 8192 8193 8448 8449 8450 8451 Up to 8477 Read/Write Write Write Read Read Read Read Read Description Logic Command Reference to 500 = 0-50.0Hz Logic Status Error codes Frequency Command – Parameter Output Frequency – Parameter Step Logic status – Parameter 28 Remember to add to the address when used in the MSG setup screen The program associated with this test is called MODBUS_RTU_WITH_MICROLOGIX_1100_AND_POWERFLEX_4_DRIVES_BROADCAST.RSS Distribution: x Open Rockwell Offices Drives Team Related to: x Inverter Use Options Use Application Experience _(Name) only Page of Generated by Date Revision D.J.Withenshaw 05/09/2007 A