Modbus_TCP-PN-S7315 Project Sample

Hi,

the example projects are installed with the setup:

https://support.industry.siemens.com/cs/ww/en/view/109745187 (current version).

https://support.industry.siemens.com/cs/ww/en/view/109752686 (previous version)

Wüstenräuber

LENGTH is the count of registers, which you want to read/write. In your case 10.

Have also a look at the block online help or the manual. There the parameters are described.

Hi,

I'm sorry, but I don't understand your problem...

In parameter DB you only parameterize, which registers the modbus block should know. In your screenshot the holding registers 0 to 499 (40001 - 40050) are "mapped" in DB11.
These are not runtime parameters! No telegram is transferred with these parameters. It is only the parameterization of the modbus block.

The runtime parameters you set during runtime in cyclical OB on parameter START_ADDRESS, LENGTH and WRITE_READ.
You set these parameters e.g.
START_ADDRESS = 0
LENGTH = 10
WRITE_READ = FALSE
and set ENQ_ENR = TRUE (positive edge) - like in example project.

With this you start 1 telegram. After the telegram is finished with DONE or ERROR, you can change the runtime parameters and start the next telegram with a positive edge on ENQ_ENR.

In the example project the runtime parameters are comment in OB. But in VAT the parameters can be set manually. If you want to set the parameters in OB, you must delete the comment lines.

Wüstenräuber

Hi,

you changed the ip address from your communication partner in DB2 manually and not with the wizard. If you change the values in DB manually, then you must change it in declaration view AND in data view. You changed it only in declaration view. 
That is the reason that the connection is not established.

But the other thing is, that your OB1 handling is not correct. You must not set ENQ_ENR in each CPU cycle. You must wait, that the telegram was finished with DONE or ERROR, before you set ENQ_ENR the next time. 
Your OB1 and OB100 are not from the original example project. Have a look at the original example project and try to understand what OB100 and OB1 do. 
It makes no sense to call the modbus block in both OBs and set ENQ_ENR in each CPU cycle and also 2 times in OB1.

Wüstenräuber