Learn how to connect a CLICK PLC to a GS4 Variable Frequency Drive (VFD) via Modbus RTU in this live tutorial Video/Demo from AutomationDirect.com.
We want a CLICK PLC to talk to a GS4 Drive over Modbus RTU. To do that, we just wire it like this. And depending on how your system is setup you can decide if you need the ground wire. In the CLICK software, let’s have the rising edge of contact C1 .. Send … a Frequency command. We want RS485 port – which is Port 3 with Modbus Control. Let’s setup the serial port. The GS4 is at node 1, so I’ll make the Mater Node. Normally we make the drive match the com settings of our network, but since we don’t have a network setup yet and we are here, we’ll just make this match the drive settings which you can find in Drive Parameters 9.1 and 9.2. Everything else looks good. The GS4 Drive’s ID is a 1. We want to write to a singer REGISTER. Using Modbus. And if we look in the GS4 user manual we see these parameters control the drive from Modbus RTU and these are the addresses. Frequency is this address so we put that here. Notice that the CLICK uses the 40 here instead of the 4 shown in the GS4 user manual. We’ll use register DS1 to hold the frequency value. I’ll go ahead and fill out the status data just in case we get an error. Perfect. Well, that set the frequency. I’m just going to copy that rung, and paste it and let’s have C2 send a RUN command. The GS4 manual tells me that is at address 4332 and of course, we have to add a 40 for the CLICK. And we will use DS2 to hold the RUN command which will be a 1. Copy that and paste it and we’ll have C3 be the stop command. It’s identical to the run command except it sends a 0 which we will store in DS3. Copy that rung and paste it and let’s have C4 send a Forward Command. That’s at this address and again we add the 40 for the CLICK. And we’ll store the forward command in DS4. Copy that, paste it, and let’s have C5 send a reverse command, which uses the same address, but will send the contents of DS5 which will be a one. And of course, we need an END instruction. Ok, Great. Let’s write that to the PLC. I’ve already created a data view with all of the control bits, created Nicknames for all of them and I put the values we need for the various commands in the DS registers. You can see RUN is a 1, Stop is a zero. Forward is a 0, Reverse is a 1. And we’ll put a frequency of 43 point 21 Hz in here. I already setup the GS4 to accept RTU commands using this video, so let’s try it. Make sure the CLICK is in RUN mode. And if we toggle C1 to change the frequency, sure enough the drive responds. If I toggle C5 change to reverse, yep, the drive got it. Toggle the run bit, the drive starts spinning. Toggle the forward bit and it starts to change direction and toggle stop and the drive ramps to a stop. And that’s all there is to it. Click here to learn more about the GS4 Drive. Click here to learn about AutomationDirect’s free support options. Click here to subscribe to AutomationDirect’s YouTube channel so you will be notified when we publish new videos.