davexr
Member
Hello,
I am trying to connect a Modicon Quantum PLC 140CPU113-03 to an AB Powerflex 4 drive using the RS232 Modbus port on the controller and through a converter to the RS485 port on the drive. I purchased an RS-485 converter, hoping to do just what I described. I have made a cable for this application using shielded two wire cable with the two wires connected to the terminal board along with the Gnd on the converter end and the other connected on term. 4 and 5 of the RJ45 connector going to the drive. I have added a 120 Ohm termination resistor on the drive end and have also connected the ground wire to the drives rs485 ground reference terminal (16). Both the Modbus connection (PLC) and the adapter connections are female so I made a straight thru cable to connect the two together.
When I try to talk to the drive I don’t seem to be getting any communication. I have tried swapping the wires but with the same results. I am working with Modicon ProWorx NxT. Is there some wiring diagram that can show me how to make the connections between the two? I am pretty sure I have them connected right but there is no indication of what is working and what isn’t. I have connected TD(B)+ (converter)to TxRxD+ (Powerflex4) and TD(A)- to TxRxD- and Gnd to Gnd.
I am fairly new to the Modicon plc’s. All I really know is what I have taught myself or learned peeking over someone’s shoulder. So here is another part of my problem. I need to know what instruction I need to use in order to communicate with the drive. I have been pulling my hair out and have been on the internet a lot looking for this information. I know it can’t be as hard as I’m making it out to be, but I can’t seem to find out from Schneider or AB or anyone else what I need to do. There is a lot of info but all of it leaves me guessing. If I can make sure that there is comm. first then at least I know that it’s a programming problem or visa versa.
Any help that you might be able to give or directions were I might find answers would be greatly appreciated. Thanks for your time.
I am trying to connect a Modicon Quantum PLC 140CPU113-03 to an AB Powerflex 4 drive using the RS232 Modbus port on the controller and through a converter to the RS485 port on the drive. I purchased an RS-485 converter, hoping to do just what I described. I have made a cable for this application using shielded two wire cable with the two wires connected to the terminal board along with the Gnd on the converter end and the other connected on term. 4 and 5 of the RJ45 connector going to the drive. I have added a 120 Ohm termination resistor on the drive end and have also connected the ground wire to the drives rs485 ground reference terminal (16). Both the Modbus connection (PLC) and the adapter connections are female so I made a straight thru cable to connect the two together.
When I try to talk to the drive I don’t seem to be getting any communication. I have tried swapping the wires but with the same results. I am working with Modicon ProWorx NxT. Is there some wiring diagram that can show me how to make the connections between the two? I am pretty sure I have them connected right but there is no indication of what is working and what isn’t. I have connected TD(B)+ (converter)to TxRxD+ (Powerflex4) and TD(A)- to TxRxD- and Gnd to Gnd.
I am fairly new to the Modicon plc’s. All I really know is what I have taught myself or learned peeking over someone’s shoulder. So here is another part of my problem. I need to know what instruction I need to use in order to communicate with the drive. I have been pulling my hair out and have been on the internet a lot looking for this information. I know it can’t be as hard as I’m making it out to be, but I can’t seem to find out from Schneider or AB or anyone else what I need to do. There is a lot of info but all of it leaves me guessing. If I can make sure that there is comm. first then at least I know that it’s a programming problem or visa versa.
Any help that you might be able to give or directions were I might find answers would be greatly appreciated. Thanks for your time.
