encoder for synchronous motor control

Dear. friends.

I have a question about selecting encoder for synchronous motor control(position,speed).

I found those things as below in the manual.

in case of EnDat 2.1 or EnDat2.2 with incremental signals, SMC20 can be used.

in case of EnDat 2.2 without incremental signals and no battery abs encoder, SMC40 can be used.

Can be used EnDat encoder without incremental signals for synchronous motor control?

or is EnDat encoder without incremental signals used for only external encoder?

in the commissioing manual, there are many supported encoders for SINAMICS.

and I found most of EnDat interface encoder has a incremental signals.

there is a comment like this in case of SSI interface without incremental signals.

"Not for motor control,
only as a direct measurement system"

and there is no comment in case of SSI interface with incremental signals(sin/cos 1Vpp)

Please help me. 

Dear. expert

I have a question about selecting encoder forsynchronous motor control(position,speed).

I found those things as below in the manual.

in case of EnDat 2.1 or EnDat2.2 with incremental signals, SMC20 can be used.

in case of EnDat 2.2 without incremental signals and no battery abs encoder, SMC40 can be used.

Can be used EnDat encoder without incremental signals forsynchronous motorcontrol?

or is EnDat encoder without incremental signals used for only external encoder?

in the commissioing manual, there are many supported encoders for SINAMICS.

and I found most of EnDat interface encoder has a incremental signals.

there is a comment like this in case of SSI interface without incremental signals.

"Not for motor control,
only as a direct measurement system"

and there is no comment in case of SSI interface with incremental signals(sin/cos 1Vpp)

Please help me.