modbus on V570

[Shailesh]

Hi everyone,

I am new at using Unitronics PLC. Currently, I am working on V570 PLC.

I am doing modbus communication on this PLC. V570 is Slave. I am checking modbus data on Modscan.

Problem I am facing right now is, I am getting all MI (integers) values on Modscan including all Bits also. But I am facing problem in reading ML (long integers).

How do I read MLxx values on Modscan? Please guide me.

Thanks,

Shailesh

[s.pratt]

Hello Shailesh,

 

On a V570, you should be able to start read the ML integers at hex address 0x7000 (decimal address 28762).  This is the address for ML0, and the rest of the ML address will increment by 1 respectively.  For a full list of the slave addressing, please go to the help files via the help tab, then navigate as follows: Communications> Communication FBs> MODBUS> Slave Addressing file.  The V570 uses the Enhanced Series slave address table.

 

Is this the address you are currently reading?  If not, how are you calling the MI and MB addresses?

[Shailesh]

Hello Shailesh,

 

On a V570, you should be able to start read the ML integers at hex address 0x7000 (decimal address 28762).  This is the address for ML0, and the rest of the ML address will increment by 1 respectively.  For a full list of the slave addressing, please go to the help files via the help tab, then navigate as follows: Communications> Communication FBs> MODBUS> Slave Addressing file.  The V570 uses the Enhanced Series slave address table.

 

Is this the address you are currently reading?  If not, how are you calling the MI and MB addresses?

Hi,

 

  Yes. Iwant to read ML registers. I want to ML7 and ML9. But where can I find this 0x7000 (28762) address in Modscan?

 

  How to read it? Is there any setting that need to be done in programming?

 

  If u have any program which is reading/writing values on Modbsus (ML registers), plz send it here.

 

 

Thanks,

 

Shailesh

[s.pratt]

Hello Shailesh,

 

we have example programs that you can load from the help tab in VisiLogic.  Depending on what type of Modbus communication you are using (serial or Ethernet) we have the according Modbus slave program. 

 

In this slave program, we just configure the port we will be communicating over, configure the Modbus protocol for that port, and then enable a "Modbus Scan" function block that will accept any Modbus commands directed to our slave ID.  This is all that we will do for programming a Modbus slave device.

 

Then, in your Modscan software, you should be able to access ML 7 at address 0x7007 (28,679) and ML 9 at address 0x7009 (28,681).

 

Please let me know if this helps.

[Shailesh]

Hello Shailesh,

 

we have example programs that you can load from the help tab in VisiLogic.  Depending on what type of Modbus communication you are using (serial or Ethernet) we have the according Modbus slave program. 

 

In this slave program, we just configure the port we will be communicating over, configure the Modbus protocol for that port, and then enable a "Modbus Scan" function block that will accept any Modbus commands directed to our slave ID.  This is all that we will do for programming a Modbus slave device.

 

Then, in your Modscan software, you should be able to access ML 7 at address 0x7007 (28,679) and ML 9 at address 0x7009 (28,681).

 

Please let me know if this helps.

In Modscan, how can we read register with address 28679 or 28681. 

Addresses for Function coils are unique like 00001 / 10001/ 30001/40001 .

 

Please tell me how to read them? 

 

Thanks,

Shailesh

[s.pratt]

Hello,

 

Only if the Modscan software is acting as a SCADA system will you need to apply an offset.

 

Coils & Discrete Inputs:  10,001 + Slave Address

Input Registers:              30,001 + Slave Address

Holding Registers:          40,001 + Slave Address

 

Hope this helps.

[Shailesh]

Hello, I have query in unitronics software that Is it possible to make aaray in memory integer in PLC logic. Please reply as per as possible . if possible then please tell me how to make array in plc logic for memory integer