synchronized axes S7-1500T

Kindly, how many synchronized axes can we control with the S7-1500T plc's ? In the below link, they mention that the 1516T can handle 55 positioning axes at 4 ms cycle. But how many synchronized axes can it control ? 

https://mall.industry.siemens.com/mall/en/WW/Catalog/Products/10339974?tree=CatalogTree

Ziemens

— Number of positioning axes at motion control cycle of 4 ms (typical value)

55

— Number of positioning axes at motion control cycle of 8 ms (typical value)

80

Right above the lines you presented from the Data sheet, there are given so-called MC resources available and MC resources required per TO.

One could also notice that, required resources for a synchronous axis is twice that for a positioning axis.

What do they mean by the following terms ? 

positioning axes : axis moves back and forth between two fixed positions . ? 

synchronized axes : axis follows another axis degree by degree . ? 

If they are like that, then shouldn't the synchronized axis need more resources from the plc ? 

So the plc will be able to control more positioning axes then it controls synchronized axes ? 

Just have a look at the technical data: https://support.industry.siemens.com/cs/de/en/pv/6ES7516-3TN00-0AB0/td?dl=de 

Section "Supported technology objects" contains all the information you need.

There you can see how many motion credits the PLC offers, and how many are used per TO (depending on the type). So this is the maximum amount in regards to memory.

The other point is the performance. This is pretty hard to say, best you check with TIA Selection Tool, this provides information about the possible timings, taking the amount of TOs into consideration.

Regards,
daviso

Based on the link you sent, i did some calculations and found the following. 

Number of available Motion Control resources for technology objects 6400 . 

. Required Motion Control resources per positioning axis 80 , so 6400/80 = 80 positioning axis . 

. Required Motion Control resources per synchronous axis 160 , so 6400/160 = 40 synchronous axis . 

. Required Motion Control resources per cam track 160 , so 6400/160 = 40 cam track . 

is this correct ? 

This is correct, if you plan to fill the PLC with only motion TOs of one type.
You probably will have a mixture, I assume. So for example some PositioningAxes, some SynchronousAxes and so on. And then you just need to add up the used ressources, e.g. 12 PosAxis + 10 SyncAxis = 12*80 + 10*160 = 960 + 1600 = 2560.

But really don't make it this complicated for yourself, just use the TIA Selection Tool, as this does all the math for you regarding the motion ressources (=memory) and also provides information if the amount of TOs suits the cycle times you parametrized in the tool. Looking only at the memory is only one part, you also need to consider the processing time of the TOs, so that you make sure to use a PLC powerfull enough to do all the calculations in the time you want/need.

Regards,
daviso