Siemens SSA61 0-10V radiator values

I've picked up about half a dozen of these to control my radiator valves.

I'm modulating these with Crestron 0-10V controllers (DIN-4DIM-FLV4). Measuring the controller output these do indeed measure 0-10V exactly when modulating the valves but the valves do not operate.
I'm using the supplied Siemens cable which is wired:
Red - 24V
Grey - 0-10V control
Black - 0V

I've tried running these on 24Vac & DC to no avail. Am I wasting my time with these?
If so can anyone recommend a suitable replacement?

The DIN-4DIM-FLV4 is actually a 4 channel 0-10V lighting controller but totally suitable for this purpose.

Cheers
-s

These operate very slowly.

The data sheet gives a "run time" of 34 seconds. Are you waiting low enough to see the full movement.

https://www.downloads.siemens.com/download-center/Download.aspx?pos=download&fct=getasset&id1=10766

Positioning speed 13.6 s/mm

Apologies for the late reply on this topic. Work has dictated that I don't get to do fun stuff right now.

Anyway an update:
I picked up a Ballorex APR-40405 (0-10V wax proportional actuator) as a test.
This works as expected (apart from the fact the control is inverted - an easy fix in programming)
So it certainly looks like none of the Siemens SSA's work. These were all brand new units out of the box so I simply don't understand why are not playing ball.
What's more, they are supposed to run an auto calibration on power-up - they don't. They all move to pretty much the same 50% position and stop.
Doesn't matter if they have a control voltage applied or not.

@bernardgreen,
Thanks for responding.
I checked all the specs before I bought these and the run time of 34 seconds is actually pretty quick compared to a wax based actuator. This is why I went for motorised. I've certainly waited long enough for them to position. Also being motorised I should be able to adjust the voltage and see them move instantly as they have a positional indicator on the top.

Cheers
-s

So Basically I'm a complete dumbass.
The SSA61's need to be fitted to the valve. Then once powered up they run the calibration.
Once calibrated they work as they should.
Lesson learned
-s