S7 315T Motion Control Hydraulic Axis

Has anyone used 315T or 317T for motion control for hydraulic axis?How do you program technology CPUs? Is it possible to use technology CPU without a driver by means of control hydraulics with analogue outputs? Do we have to use IM174 module or can we use other encoder and analogue cards instead of IM174?

Thanks.

We have used both the 315T and 317T. The best results we have found is using the IM174 module as this integrates well with the Technology Configuration software. The Technology package is easy to use and the Motion Control blocks in the PLC code are very flexible. We have used ET200S High Feature modules as the SSI/Analogue Feedback/Analogue outputs on other projects. This is possible and works well enough but the cost of 3x ET200S axis is more than the cost of the IM174. If you're using SSI feedback then the IM174 is the best option.
The only other thing we do is to add a pressure loop card (we make our own) that is added to the valve output. The Synamics controllers can integrate pressure feedback into the control loop but the 317T/315T cannot. It is possible to tune the system well without the pressure loop card but for greatest stability at slow and high speeds we've found the pressure loop to be invaluable.