P.L.G freqrol

Hello,
Following a misunderstanding of the freqrol drive and its configuration, I would like to exchange it for a more recent generation variable speed drive.
But I would like to keep its servo control.
The freqrol documentation mentions a P.L.G. spindle encoder.
Does anyone know what P.L.G corresponds to?

Does the PLG connection (below) correspond to a standard incremental encoder connection? A+/A-/B+/B-/Z+/Z-/5V
/GND
If yes, what do I wire Z+/Z- for?

1-PA
2-RA
3-PB
4-RB
5-AGA
6-NI5C
7-PZ
8-PI5C
9-AGA

the plg will be connected to a 7i77 card

My guess would be:

1-PA A+
2-RA A-
3-PB B+
4-RB B-
5-AGA Shield?
6-NI5C 5V GND
7-PZ Z (single ended)
8-PI5C +5V
9-AGA Shield?
 

Thank you for your feedback,

to check the encoder connection i dismantled it until i could see the wiring on the connector, below is the wiring for the encoder output connector

  
I have the impression that the 3 channels A,B,Z are single-ended, can you confirm this?

Between the connector and the encoder there is an electronic card with the following outputs

V+ - RED
G   - BLACK
V-   - BLUE
CG - GREY
G    - YELLOW
B0   - WHITE
A0   - GREEN

if this is true, the encoder wiring on the 7i77 should look like this?