quantum and atv71

Hi all

Got a question about comms between a quantum and an atv71 over modbus tcp/ip.
Normally I would do this using i/o scanning but for this client they cannot switch off plc so it has to be done manually with read/write blocks.

Now in io scanning you would read and write at register 1-11 (io scanning tables on atv71)
If i use normal read/write blocks I am not getting the values.
If however i read from the variables own registers ex. 40001 i do get values but I dont want to create a new read condition for every variable.

Thanx in advance for any help

Hi

Just guessing here (I always use io scanning), but have you set up the drive as if it was being io scanned, this should set up a block of data that the plc can then read/write using the readvar/writevar instructions. The block should appear at the address you would set up in the io scanning table.
PS I would be interested to know if this works

Hi Geoff.
When you use IO scanning do you use register 1-11 for reading and writing as shown in their examples in Unity?
Also i'm not sure that the standard in out tables on the atv 71 is the same tables as the ones you setup using the webserver. I think this is where my confusion comes in.Because the normal in out tables does have proper registers to read from unlike the registers 1-11 shown using the webserver io tables. I will ask the client to try the normal table. Think that will solve my problem. Will let you know

Setup the io scanning table using the web server interface. You can set up the table to read/write any of the parameters in the drive.

Yes you read from 1-11, but I think the data will actually start at 2 (this will contain the first parameter setup). I think the first word back is reserved (but I think you have to read it)

We did a quick test and you have to use the in out tables on the drive and not on the webserver. The tables on the drive starts at register 12761. So enter the values you want to read/write in these tables and then you can use normal read write blocks. If you use normal read/write blocks on i/o scanning doesnt want to read at register 1-11. It may have something to do with the tcp/ip address blocks map index

nice find