Identifying the motor type in a microscope stage

[amaschas]

In the continuing saga of my attempts to get and old 2-axis microscope stage working, I've run into a bit of a roadblock in identifying the type of motor that drives the two axes. I initially assumed it was a 2-phase stepper motor, but I've found some information that indicates it might be a servo motor instead. The motor in question looks like this:



I has 4 leads, a red/black pair and a blue/white pair. The blue/white pair is marked +/-, and the red/white pair is unmarked. There's also a symbol on the top that you can sort of see here:



There's also an encoder mounted on the end that has 4 blue leads:



I've found similar motors being sold:

https://www.capitolareatechnology.com/escap-23hd-motor-11-216e-204-1-leica-pn-302-050087-003.html
https://myvisionsurplus.com/products/escap-motor-gear-23hd11-216e-204-5

And this post which describes it as a servo with an attached encoder, but the motor in this post has 6 pins total, whereas mine has 8 if you include the encoder:

https://rogerparks.com/instructional/escap-16-gear-motor-encoder

In the documentation for the controller for this type of microscope stage, however, the pinout for the motor inputs would seem to indicate that it's a stepper, as the motor pins for the axes are documented in this format on page 7 of the linked PDF:

Motor 1, Phase 1 +
Motor 1, Phase 1 -
Motor 1, Phase 2 +
Motor 1, Phase 2 -

https://www.marzhauser.com/fileadmin/Dateien/Downloadbereich/Steuerungen/TANGO/Treiber_Firmware_und_Dokumentation/TANGO_Desktop_E/TANGO_Desktop_Operating_Manual_EN_130409.pdf

Any help in identifying what kind of motor this is would be appreciated!

[H.O]

Definitely looks like a PMDC servo motor.
Tachometer on the back (blue wires), motor armature (red wires) and with the encoder mounted on the output shaft.

The ESCAP16 gearmotor with encoder you link to lacks the tachometer, hence 2 wire less.