Joe Tauser

I opened both the files and there is only one line. Are there supposed to be more? Also, type out in your post what a line is supposed to look like in the .csv file. Joe T.

Don't call the Read and Write functions continuously. Once per read or write is enough. I reconfigured your table and gave you some buttons to run through it to manipulate the row pointer. Study each network and open the Read and Write Row tables and look through them. If you want to display a string you have to specify a vector of MIs as each one can only hold two ASCII characters. Joe T. test JT.vlp

The Modbus section is in appendix B. Please verify that you have set the switches and parameters according to pages B-1 to B-5. Verify that you have the jumpers on the V350 set to RS485 as outlined in the V350 Installation guide. Tell us what the VFD slave ID is set to (C072) and verify your serial cable connection - the drive is an RJ45 8 pin and the PLC is an RJ11 6 pin. Pin 5 of the VFD cable should go to pin 1 of the PLC cable, and pin 6 of the VFD cable should go to pin 6 of the PLC cable. The jumpers and PLC cable diagram are on page 7 and 8 of the V350 Installation guide. Then tell us exactly what you want the PLC to tell the drive. Referencing pages and commands in the Hitachi manual would be helpful. Joe T.

I'm not understanding what you're saying here. Joe T.

Something isn't right - the delimiters you're specifying are not appearing in your excel sheet. Post your program and one of the .csv files it makes. Joe T.

I asked you to post your program and find a link to the needed Hitachi Modbus documentation. I'm not going to go digging to support a product I don't sell (Hitachi). And you you need to upload your .vlp file to show that you are trying to solve this yourself as well. Joe T.

I stand corrected. Maybe I should stock some Gaffer tape and put a JTA / Unitronics part number on it. Joe T.

Your RC15 program isn't including them in the STRUCT collect block, as I only saw DW 22 and DW32. So they're not being sent. UniCAN is a one-way transmitting protocol - the V1210 can't "read" the RC15. What exactly are the addresses of the Run bits you want sent back to the V1210? Joe T.

In net 2 you have Socket 0 Connect four times to different IP addresses. You can't do this - the socket can only connect to one at a time. And you have to close the socket each time. You should also use a positive transitional for this, as the Socket won't talk while it's Connecting. It looks like want to talk to the valves every 5 seconds. You also don't have a coil for MB 435 Socket 0 Close. You may need a short delay (0.1 s) before switching IP addresses to another valve to let the Modbus finish. I put this into one of my State Machines as this is what I do for fun on a Saturday night and this is a good example for other users. The pointer / Equal block method allows more control. I did this in VisiLogic 9.8.79. Let us know if it works. Joe T. sample1040tcpip JT.vlp

You're looking for a deadband control, which can also be done this way in addition to sgull's suggestion- You can put MIs in place of the #400 and #600 which will allow you to adjust your control from screen variables. If you're feeling brave post your program. I'm curious to see how you've progressed. Joe T.

If you post your code we may be able to help shorten your troubleshooting time. Joe T.

Post your code so we can look at your configuration. Joe T.

OMG, Aus. Duct tape? I thought I was the only one who did that. As Aus says, try connecting the sensor directly to the terminals. If it's still jumpy then try replacing the module - in RTD mode these are nothing more than glorified ohmmeters and they are multiplexed into a common A/D converter. If you're having an problem on multiple channels there's probably something wrong with it. Joe T.

Send these screen captures and a copy of your program to support@unitronics.com. This forum is moderated mostly by users and you may or may not get an answer here. This one is over my head, having never used J1939. Joe T.

All Vision PLCs work the same way when it comes to Modbus, so the ladder code in the V130 example will work in the V350. Typically the Modbus master is using the RHR #3 (read holding registers) and PHR #16 (preset holding registers) commands when talking to a slave such as a VFD. The picture of your code uses function #8 Loopback Test, which isn't going to do anything except prove the PLC can talk to itself. Post your actual PLC program and a link to the Hitachi x200 communication reference containing the Modbus register table. Joe T.

You're getting ** because the value being returned by the module is overflowing the number of digits you have on the display variable. If a thermocouple is not connected the module will return 32767 (look at the ATC8 specification sheet on page 10). You could put some logic in for each input that looks at the value and if it's greater a certain number (say 30000) then you can force it to zero. You may have to copy the value to a buffer register for display to be able to do this. Joe T.

Any of the Unitronics Vision or UniStream PLCs can be a blank slate capable of both Modbus RTU and Modbus TCP communication in both Master and Slave mode at the same time. Whether a unit is a server or client depends on the point of view of data flow, but generally the "Server" is the slave and the "Client" is the master. Your requests #1 and #5 are kind of ambiguous and need more details. As to what hardware you need, I would lean toward the UniStream family as it has much more powerful networking capabilities and the Modbus is easier on it. All you have to decide is how big the display needs to be and a list of I/O connected to it. Joe T.

Can you show an example of "interfering"? Joe T.

Have you tried the String Length function (in the strings menu)? Joe T.

1. In the WCB1 module you can configure an HS block as a counter, which includes a Frequency value in the IO struct. When the Frequency goes to zero you've stopped. Look at both the installation and the specification data sheets for the module. 2. The WCB1 only has 0-10V outputs, so you're not going to be able to make your drive go in reverse with the speed signal. It should have a reverse digital input you can use. Use the Accel and Decel values in the drive; there is no need to program these in logic unless you want to stretch them out longer than your programmed parameters. As far as limiting the value of the output, use a >= block to limit your output value to a maximum- 3. You'll have to program the machine's behavior when the E-stop is pressed, which brings up my personal favorite way of programming - the "State Machine". Look at this post and Visilogic example- One of the states is called "Idle". This is not the same as the UniLogic "Idle" function (I would never use that). You'll need to create a state for "Paused", triggered by the E-Stop, where you copy the current state number to a buffer so the PLC remembers where it left off. You can then choose to exit that state and either return to where you were or program an orderly shutdown to the initial condition. I didn't say this was going to be easy, but if you beat on it and post your code we can be of more help. I just downloaded and installed UniLogic v 1.25.56, so use this version. Joe T.

Dan- You are really going to be freaked out when you realize Unitronics allows multiple coil stacking and curvy logic joints- If your primary focus has been the various flavors of RSLogix, I totally understand your irritation with the Unitronics way. After I originally read your post I considered the packages I've also programmed- AB SLC500 + uLogix, PLC 5, RSLogix 5000, Omron, Mitsubishi, Idec, Siemens, and the Modicon x84 series. As you state, it seems to be a toss-up as to rung-starting methodology. None of them were especially difficult to figure out with the exception of Omron, with it's little key-initiated edit/insert mode that's not really explained anywhere. And no subroutines, just a continuation of segments. I hated working with that product. In the BeforeTime, when there were only two real PLCs in the US market (AB and Modicon), it's interesting to note that AB always used the rung-and-branch method while Modicon used the 7 x 11 network method. You could have up to 7 contacts hanging on the rail with interconnecting logic This was the comment that raised my eyebrows- Especially on your first post. This software is free. All of it. Always has been. So is the forum. And support requests. It does work, albeit with some quirky nuances. I was just quoted $950 for an additional FactoryTalk View ME license to allow me to program the $5,000 PanelView Plus I just bought. Add that to my $800 annual TechConnect contract. It's one thing to pay for software, it's another thing to get totally bent over for it. Hopefully you can get past the software weirdness and find the product to be a good and cost-effective solution. Joe T.

By ohms law, 20 mA through a 500 ohm resistor gives a 10V output. Joe T.

Many, many moons ago when I sold Red Lion they used a form of serial communication called a "pulsed 20 mA current loop". It was not analog signal, but the reference to 20 mA made people think it was. HART rides on top of a 4/20 signal so they're probably talking about using a resistor at the receiving end to generate a loop for it to exist. It is rather weird. If you get the Modbus option this would probably be helpful- http://www.bb-elec.com/Learning-Center/All-White-Papers/Current-Loop/How-do-I-connect-the-Current-Loop-Converter-to-my.aspx You'll know more when you have it in hand. Empirical data is the best data. Joe T.

I do not (I had to look up Greengrass) but I am not a Unitronics employee. Try sending a query to support@unitronics.com to get an official answer. Joe T.

Does this happen when you're trying to download a program? Joe T.