HonzaD wrote:

Hello MBE,

Just to make this clear. The manual says about modbus tcp: "Only one device can be connected to the device at one moment." It's a bit uncelar what device is the Comet ethernet transmitter and what is not.
I guess this means that only one PC/unit  can poll the comet ethernet devices.

Yes, you have right. Description inside user manual is a little bit unclear. For the next manual revision we can think about changing this description. For this moment Tx5xx/P8xxx/Hx5xx has only one socket Modbus TCP server. Only one Modbus client can be connected at one moment to the device. But we are talking about Modbus TCP protocol only. Ethernet device supports many other protocols, which can be uses at same time.

But that the same PC can poll/collect data from many comet devices (one after the other). Is this just about true?

Yes. This depends on your DAQ software (SCADA system, etc.)

Excelent, just what I wanted to hear.

I noticed that with an invalid adress (40000) among other correct adresses the communication didn't work (using wonderware Modbus TCP) . Are there other limitations?

I double check this. There is no limitation of ModbusTCP server to TCP port 40000. I think this limitation is inside your InTouch software. ModbsuTCP port number can't be set to this values:

He he. that was a Modbus adress i ment, not the TCP port. I don't remember the storry any more but there is a never ending conflict where some systems use 40000 as the first adress as documented in your system, while others name that same adress 40001 as wonderware and many others does  as I have seen both here on the forum and other places.
Using that 40000 seemed to make the communication stall. Or it might have been initial problems that remained in my test setup.
Thing is that to me it seemed like there were two things I HAD to do to get the system to work: Disconnect the TSensor software and remove any invalid adresses.