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Posted

I have some boilers managed by a few V350's, and am looking to do some integration with them.  I am looking to view the ladder/hmi project, but do not have the original files.  Is is possible using VisiLogic to download the project from the device to explore and potentially tweak it as necessary for our integration?

Thank You

  • MVP 2023
Posted

Hi Crazi and welcome,

The answer is yes....possibly!  You might be getting into "PLC program intellectual property issues" here, too.

The problem is that it may be password protected, or that the program loaded into the 350 is not the type that enables uploading.  You can only really find out by accessing the unit with VisiLogic via either the serial port or ethernet.  Upon correct connection, Visi will tell you what it finds.

If you find that you can't get the program these ways, check what is on the micro SD card if one is fitted.  There may be a user program or total backup stored there, but again you might need a password.  If the unit does have a micro SD in the slot, use the Info mode to go to System and explore the SD card from there.  If any user program comes up then it may or may not be the one in use, (compare it to the name of the program in use...also accessible via Info  mode) and it may or may not have a password.  You can pull the card and get into it directly if needed.

I have left out many of the steps involved here as it is all fairly straightforward and logical. 

Cheers,

Aus

Posted

No sd card, and no ethernet port (has 2 serials, both configured for modbus - one talks to the burner controller, the other to the existing management system).  Ultimately, I'm looking to discern what is available on the second modbus, and hopefully leverage that for the sequencing I want to perform.

Posted

Checking back in.  Finally got the opportunity to plug into the controller.  Not much luck though.  Any operations in visilogic to try to upload or even things like get hardware info, etc return an error.  Watching from info mode, COM1 does switch to PCOM, 9600,n,8,1 whenever the laptop is trying to talk to it, but apparently is not responding in kind.  The cable seems to be good, as I can see MODBUS traffic in realterm.  Is this bland error the expected behavior if the PLC is locked down?

Again, thanks for any assistance.

Posted

What error do you get Crazi?

Did you try putting the PLC in stop mode and then communicating?

Typically if the PLC is password protected you'll get a prompt to enter the password before the upload starts, the program being password protected won't stop you from going online and viewing the controller or getting the hardware information.

Posted
On 10/31/2016 at 8:45 AM, Joe Tauser said:

Make sure your baud rate is set to 115200 if you are trying to talk to a V350.

 

Joe T.

I'll give that a shot.  I had it set to 19200, which is what the modbus communicates in, but I also noticed that when it switches to PCOM mode, it's displaying as 9600 baud on the SERIAL page of info mode.

Mostly unrelated, but we also had one of them lose it's programming during a power outage yesterday.  I'm assuming I'd be able to copy the program from one to the other via microsd, even if it's password protected, correct?  Haven't read up on the process for doing that.

Posted

This is the error I receive on any attempt to communicate with the device from visilogic, no matter what baud rate I set it to (the chosen baud rate is only used for an instant, than the PC and the v350 switch to 9600, and then it fails out.  The USB-Serial adapter I'm using communicates fine to the v350 to poll MODBUS registers.

1103160626.jpg

  • MVP 2023
Posted

I know this is a dumb question, but is your USB-serial adapter actually 232, or 485?  You say above that it works ok to poll Modbus registers, so in theory this implies it is a 485 unit.  Yet to access the 350 via serial from Visi as discussed during the thread, it needs 232, not 485.   (as far as I know....happy to be told otherwise!)

And a later edit:  Again perhaps I am wrong, but further to this observation, if you are indeed getting into the unit on 485 with an existing cable, perhaps you need to get a correct cable as well.  If you are getting in on 485, you are in theory accessing pins 1 & 6, which won't work for Visi.  Check out cable pinout diagrams.

cheers,

Aus

  • 3 weeks later...
Posted

Sorry for the very late response.  When I was trying to get Visilogic to talk to it, I was using a 232 adapter, but I also used a 485 adapter (with an appropriately pinned adapter cable) and a modbus tool to exchange parameters.

  • MVP 2014
Posted

You can quite happily poll Modbus registers using RS232.  It's just that you can only have one slave and it can only be 25 feet from the master.  Also, I have found that even if the Unitronics COM port has been set up for RS485, if you plug a standard RS232 4-pin cable in it will still  talk RS232.

The post from Cam suggests putting the PLC into stop mode, which is a good thing to try.  That will prevent any settings in the project (such as Modbus) from taking over the port.  You can view and if required set comms parameters via the info mode and the project won't override them while in stop mode.

If you still have no success, I suggest trying bootstrap mode (power down the PLC, hold your finger on the touchscreen and power up, then follow the prompts).  This will isolate any effects of the OS and program.  In this mode you must have Visilogic set to 115200 baud and you won't be able to upload the project in this mode.  This will at least confirm whether you have comms to the PLC.

 

It is also possible to lock out Visilogic communications, see old forum post below:

http://www.unitronics.com/forum_old/topic.asp?TOPIC_ID=2034

If you can get into the info mode you can check and if needed change the value of SB314

  • MVP 2023
Posted

Good call Simon, on SB314, I'd forgotten about this SB as I rarely use it.  Too many SBs, not enough brain cells!!

And for Crazi, perhaps the simplest long term solution if nothing else works is to get the cheapest vision controller that you can possibly use on another project, and make sure you can access it ok with your equipment.  If you have that going ok, then go to your existing controllers and try from the known good communication config.

For Simon......re Modbus and 232, I digress a little off topic, but are you saying that if I tried to access a Vision with Modbus init for use on 485, I can access the same registers with 232?  I know about the port still running 232 when set for 485, (and isn't it only one port can do this on multi-port models?) But I could poll a slave init to 485 with 232 successfully?  Maybe elaborate a bit here, or perhaps start a new thread just as an info source?

cheers,

Aus

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