Siemens S7-400H system Modbus TCP/IP connections.

[MAKSM]

Hello All,

For S7-400H system, can we make this redundant PLC (connected to one uplink switch) to communicate simultaneously with 3rd party HMI (of brand X) and 3rd party DCS (of brand Y) over Modbus TCP/IP while having one quantity of Simatic Modbus/TCP license (6AV6676-6MB10-0AX0) alone?
Please advise.

Thank You.

 

[Ken Moore]

You will need the redundant license from Siemens (which you have), plus a 443-1 (ethernet) communication module in each of the redundant racks. When you buy the license, you will also get special redundant function blocks, where you can add both connections from Netpro. The function blocks automatically switch to the active controller. I do not know the current price, but a couple of years ago it was around 6500 US dollars. However, you may be able to get a discount if you are doing a large project.

Are you using PCS7 (version?) or Step7? When you install the license you will get a activation request number, you have to send this to Siemens, they will send you a license number that you plug into the Redundant blocks. Siemens recommends you add the license number to a DB, and then reference the DB to the blocks. I do no know if Siemens can be configured as a Slave, I have always used it as the Master.

Then you can connect to your Modbus "network" via a switch and only have one connection at the HMI or DCS.

 

[erikbenson]

Yes, it is possible to make a redundant S7-400H system communicate simultaneously with a 3rd party HMI of brand X and a 3rd party DCS of brand Y over Modbus TCP/IP while using only one Simatic Modbus/TCP license (6AV6676-6MB10-0AX0). However, it is important to note that the license is only valid for one device, so if additional devices are added to the system, additional licenses may be required.