tim.snelling

Good Info Joe T. !!!

Joe T., Thank you for the pointer. I had to move on to other projects, and I'm going to be getting back to this project soon. It appears that the Advanced Modbus Functions will give me what I need. Gabriel, Your idea could work, however these PLC's will go into many sites, with a different number of PLC's, and possibly a different range of IP's, so setup would be more difficult. But if I can't get the socket to close using the Advanced Modbus Functions, then I may be forced to do something like you suggested. Thanks guys, Tim S.

Hi, I need to have several UniStream PLC's (Modbus Master TCP), that connect to a Modbus TCP Slave. The Slave provides Ambient Temperature, so reading the Holding Register from the Modbus TCP slave every 30 minutes or so, is adequate. In UniLogic ladder logic, I set the Active Periodic bit "On" with a 30 minute timer, then it reads the holding register. After a successful update, I then turn "Off" the Active Periodic bit, but the PLC's socket connection does not close, and the Status of my Modbus Master remains at "1 = Good, No Errors" for the entire time in-between the 30 minute read from the Modbus Slave. Can someone tell me how to close the Modbus TCP socket connection on port 502, using the UniLogic ladder logic. Thanks, Tim S.

Shown below, I purchased one of these iPhone ethernet adapters, and I can now VNC into my PLC (that has no HMI) using my iPhone, and a crossover cable. So far it's working great. Just thought I'd pass this on. It did take a little getting used to, to hold the curser down for several seconds, to access the UniApps. But once you get the hang of it, it's not difficult at all. Tim S.

Hi Joe, thanks for the help. I do have a full understanding of Modbus. I'm just new at UniLogic and UniStream. I simply wasn't able to find any method for a Multi Register read. FYI; I wasn't confused. My wording was the exact wording in the Error Description. I have no doubt your method works, but after all that typing... what a pain. I did finally find something in the help for a "Batch Operation". There's a barely noticeable drop down arrow on the Add New Operation button. So if you click that tiny little arrow, a drop down is displayed. Then select "Add New Operation Batch", then UniLogic will allow an entry of the Array Name, without having to back space. That drop down "arrow" could be a lot bigger. But I'm learning, one day, and one issue at a time. Thanks Again, I appreciate any and all assistance. Tim S.

I'm back to being confused, the Write/Read Multiple Registers tab, apparently does exactly that. It Writes and then Reads the registers. I only need to Read. So how do i Read 122 holding registers, without exceeding the limit of 64 operations? Tim S.

Never mind, I'm blind 😒. I now see the Read Multiple Registers tab. TGIF Tim S.

I need to read 122 holding registers from a modbus slave in UniLogic. But there appears to be some crazy low limit of reading only 64 holding registers. I must be missing something, or doing something wrong. Any thoughts? Thanks, Tim S.

If you are interested, this is the reply that I received from my Support Ticket. With the UniStream, you can have dozens of devices connect to the PLC on the same port. All you will need to do is set up 1 Modbus TCP slave instance, and point all of your devices to the same port (502). So it appears I can delete my Slave on port 503, and all should be good, with dual connections (or more if needed) on port 502 Tim

Thanks Guys, I appreciate everything. My problem is, I can't test anything. Hardware is being assembled in control panels, at a vendor. and then shipping to the job-site. I have to go to the job-site, to connect up all of the external IO. And I'll be expected to have the logic close to completion by the time they put power to the panels. The only good thing at this point, is one of the Masters is only for monitoring purposes, so if that one isn't working when the site goes live, it wouldn't be tragic. But I do need to resolve this soon. I went ahead and submitted a Support Ticket. Thanks, Tim

Thanks AUS, With the vision 230 PLC's, we are establishing a remote socket connection from 2 different applications that run on a windows OS workstation PC. One application is connecting on the standard Modbus TCP port, and the other is connecting on a non-standard port. Both applications communicate with the PLC, and we have never had any issues with this. It's a simple setup for the 2nd socket connection via VisiLogic. So i'm confused with this issue showing up as an error in UniLogic... We want to duplicate/improve the V230 program with a UniStream PLC. If it was PLC to PLC, I assume UniCan would require CAN comm modules on each PLC? Thanks, Tim

This sounds like a step backwards, as I've been doing this for about 10 years in VisiLogic on a V230 PLC's, and I've never had any issues. I switched to Unistream, to upgrade, I need this to work, it doesn't need to be 100% reliable, do i need to create a support ticket? Thanks, Tim

I want 2 different ModbusTCP masters to connect to my PLC. I set up 2 ModbusTCP Slaves but I am getting an Error, "Both Slaves have been set to the same communication protocol." They are set to different ports, and different Node ID's. Why am I getting this error? Thanks, Tim Snelling

Thanks Denis, i was able to get that to work.

Is there any way to add a Symbol in the Text After field for a Numeric Box? Something that isn't available from the Symbol button? For Example the Ohm/Omega Ω symbol? Thanks, Tim Snelling