[Modbus slave adressing]

Bumping this one since I got another question as well.

I'm trying to establish communication with the V130 trough a ModBus simulator on a PC, often enough I can get a connection but I haven't been able to read or write anything to the PLC. I've tried several softwares and all of them has a field "Slave ID: ". Is this the ID filled in the Modbus config FB? I.e 255?

Also, have anyone here used some kind of Modbus simulator with a Unitronics PLC they know to be good? Several of the ones I've seen are quite messy.

I would really appreciate some input, both on this post and the first since I haven't been able to figure that one out either.

Regards

Anton

[Modbus slave adressing]

Hi all,

I have a question regarding slave adressing on Modbus.

We have a V130 which we want to use as a slave on a Scada system. When I read about slave adressing in the help file the pointer value offset is given for each data type, no problems. However, when I read the examples (and also different topics regarding modbus here on the forum) another offset seem to occur. For example when writing a 3-bit vector of outputs starting at O8:

"SCADA as the Modbus master to color PLC:

• Convert the HEX address to DEC.
  In the SCADA application, set the Slave: Start of Vector parameter to 46393 (30001 + 16384(4000h) + 8) and the Force: Vector Length parameter to 3, enabling the Master device to write to O 8 - O 10 within the slave Vision controller."
  

Where does the 30001 come from? The 4000h is obvious since it's mentioned in the help file.

A similar offset of 40001 seem to appear when reading/writing MI:s, 400001 for MF:s and so on.

I must be missing something fundamental since I can't find any information about this offset.

A couple of words around this would be much appreciated.

Cheers from Sweden

Anton

[Alarm acknowledge V130]

Great answers, thanks guys!

Now I'm informed, I'll pass this on to the client in question.

BR

Anton

[Alarm acknowledge V130]

I'm bumping this one again since I haven't been able to solve it and the client is adamant that the acknowledge button is another one than F2.

So, is there any way to user define the ack button on the V130? Help would be very much appreciated.

regards

Anton

[Alarm acknowledge V130]

Hi again,

Since no one has yet answered, lets put it this way:

How is the alarm acknowledge function supposed to work? Isn't it just to specify a bit as "Acknowledge bit" and when the cause of the specifik alarm is gone, let this bit go high (i.e. by pressing a button) and then the alarm will be acknowledged?

In the alarm examples I've seen the acknowledge bit isn't used, so I'm a bit lost.

regards Anton

[Alarm acknowledge V130]

Hi,

I'm having some issues regarding alarm acknowledge on my V130. I have a couple of alarms I would like to be acknowledged by a button connected to an input, the input sets a MB which is choosen in each alarm config as "acknowledge bit". I thought that this would acknowledge the alarm just as the selected MB goes high, but it doesn't work.

Instead, the "F2" button is the acknowledge button, in the plc-project the "F2" button isn't used anywhere regarding the alarms. Is this maybe some default that isn't possible to change?

regards Anton

[Create new FB]

Okay, that's a bit disappointing. I´m sure I´ll solve the problem anyway but it would have been nice.

Thanks for your answers.

/Anton

[Create new FB]

Hello Unitronics forum!

I have a question regarding function blocks. Is it possible to create your own fb? I´m new to Unitronics and I´ve tried to find info about this without any luck. I´m about to control a number of motors in a similar way and I thought a fb would be convenient to acheive this.

best regards

Anton