Connecting Sitran P + Sitran T via PA/DP profibus to PLC S7-300

Hello Tamer;

A Profibus-PA is a subordinate bus to Profibus-DP (in Siemens' world), so you need an intermediate hardware to setup your PA line.

You have 2 choices, with Siemens hardware (there are other providers, such as Pepperl & Fuchs and Procentec): you can simply use a DP/PA coupler, or a DP/PA Link.

Using a coupler on the Profibus-DP line is the simplest arrangement, the coupler does not have to be configured, you use the gsd (Profibus-PA) file for your instrunents to set them up on the Prodibus-DP master's configuration exact;y as you would a Profibus-DP slave. Hoiwever (there is always a however...) the maximum speed of the bus (Profibus-DP) must be brought down to 45,45 kB for all slaves on the network.

Using a DP/PA link is a bit more complex, but allows you to run the Profibus-DP at its required speed (up to 12 MB) independantly of the Profibus-PA lines (up to 5 per link).

For more information look at the following documents:

How do you set up the DP/PA link and how do you configure the DP/PA link and DP/PA coupler?

SIMATIC Bus links DP/PA coupler, active field distributors, DP/PA Link and Y Link

Note that to calibrate and set up your instruments you will also need a licensed PDM software`; see here for more information:

Process Device Manager SIMATIC PDM - Siemens

Come back to the forum if more details are required.

Hope this helps,

Daniel Chartier

Hello Tamer;

Normally the transmitters you mention are designed to be installed in a connection head, which generally contain a LCD display (to show the current measured value, for instance) and a few buttons (Mode, Up, Down for example) in my experience. in this case we usually used the Mode button to o to Node Address mode, and the Up and Down buttons to set it in the accepted range of the network.

I do recall that some models of connection heads were blind (no display), specially in case of explosion-proof (Ex or ATEX) configurations. In this case we did the setup of the addresses through PDM, I believe.

It would be good if you sent us he model numbers of your equipment, sensor and connection head, so we might find more precise information for you.

Hope this helps,

Daniel Chartier

Hello tamer;

Your picture reminds me of my teaching years, and of something I used to tell my students regularly: "Respect your equipment; clean the d..mn thing!".  ;-)

So, here are the operating manuals of your instruments, you could have located them easily using the search box at the right of this page and the part numbers provided by you. I added a few comments:

SITRANS P DS III/P410 with PROFIBUS PA

If your model of Sitrans has a LCD display and control buttons then you can set the node address using the Mode button (mode 15), see this extract:

The node address of the device on the PROFIBUS, the so-called bus address, is set in mode 15. The permissible range runs from 0 to 126.

Note

Do not change the bus address of the device while your system is running.T he device will then no longer be visible from the application program.

If no display is available, use Simatic PDM to set the PA node address ( menu function “Set Slave Address”)

Sitrans TH400

You must use Simatic PDM to set the PA node address ( menu function “Set Slave Address”).

Hope thios helps,

Daniel Chartier