Ironhorse ACN & ACG VFD Modbus TCP Setup from AutomationDirect

We’re setting up two Ironhorse VFDs for Modbus TCP communication. One ACN series and one ACG series. The setup is almost the same, but I’ll point out any differences along the way. Of course, first we need to install the modules. On the ACG, it’s simple. Remove this cover, connect the short cable between the drive and the card. Snap the module in to place, and tighten the screw. The card has two Ethernet ports for daisy-chaining drives, plus a covered connector for a PC or remote keypad. Just pop out the cover if you need to use it. On the ACN, the installation takes a few extra steps, but it’s still pretty straightforward. The option card also has a covered RS-485 port, so make sure you use the proper port for Ethernet. Before installing, switch one up for Modbus TCP. Remove the drive front cover and the module cover. Disconnect this wiring connector. Remove the keypad adapter board. Then, install the extenders. The short one goes on the right, and remove the screw on the left to install the longer one. Now, snap in the card, secure it with the screw that came with the card, and the one you just removed. Reinstall the keypad adapter board. Reconnect the wiring, and snap the ETH cover back in place. When the cards are powered, the CPU LED should flash, confirming it’s communicating with the drive. If it’s not flashing, please reinstall the card. Now let’s set up our drives. We’ll assume you’ve already set the motor parameters. If not, please see the video linked above. Now let’s set the drive control to the network. On the keypad, use the up arrow to get to DRV and set it to 4 for Fieldbus. Then go to FRQ, and set it to 8 for Fieldbus. Next, assign network settings. The IP address is in parameters CM10 through 13 Subnet mask is in CM14 through 17, and Gateway is in CM18 through 21. I’ve checked the PLC program, and it uses 192.168.1.101 and 192.168.1.31. Since dot 101 is the default for the ACG, we’ll leave it. For the ACN, we’ll set it to 192.168.1.31. And use the default for mask and gateway on both. And to retain these settings through a power cycle, they must be stored by setting CM94 to 1. I didn’t bother with this step on the ACG since it’s all default. That’s the basic setup. But our PLC program also uses the virtual inputs, so let’s configure those too. So, set CM70 for virtual DI1 to 46 for forward jog, and CM71 for virtual DI2 to 47 for reverse jog. We have a two-part Modbus RTU series linked in the description, and above, please see that if you’d like a closer look at Modbus. TCP works mostly the same, but keep in mind, the addresses are offset by one. For example, the status word is 40773 in RTU, but 40774 in TCP. All the Modbus addresses can be found in chapter 5 of the drives’ user manual. Now for the PLC program. If you’re using one of our PLCs, we provide example programs for every drive and PLC. Here, I’m using a CLICK PLC and a C-more HMI for interfacing. The CLICK data view makes it easy to manipulate values, but I felt like making a C-more project for this. The CLICK program is well-documented. We set the number of drives here; this controls message stepping. If you need more than 2 drives, you’ll need to add more messages. The program calculates RPM from the frequency command. Error and success counters help monitor communication. Bits for start/stop and direction are packed into word DS1103. So, the messaging flow goes like this: First, we read from Drive 1: 8 words starting at 40785, which include output current, frequency, RPM. With the drive being stopped, we only see bus voltage right now. Next, we write the frequency command from DS1101, along with RPM and operation bits. The drive runs at 30 Hz, and we see the expected feedback. Drive 2’s messaging is exactly the same. So we tell Drive 2 to run at 60 Hz. And again, we get the feedback we expect. Finally, lets test the jog with the virtual D'is. And that also works as expected. That’s it! Two Ironhorse VFDs running over Modbus TCP. For more drive videos, look here. To buy drives for your applications, click here, and subscribe to be notified of new products and solutions.