Need help about servomotor pinout

Hello, first of all, it's first time I'm working with servomotors.

I attach a photo of the motor specifications:
Could someone explain to me what are the G+ and H- pins used for? are they IN or OUT?

Finally, I Would really be grateful if someone recommend me bibliography about servomotors .

MAny thanks in advance

I don't know for sure, but my 1st best guess would be; those are the connections for tach feedback.

many thanks Todd , i just confirmed they are tg feedback . Do you know where i can find information about servomotors ? there are many things i dont know yet.

Wikipedia might be a good start.

That looks like a DC servo to me, with an attached tachometer.

Do you also have encoder feedback?

Its pretty dark but you can also read "A,B,Z" on the label

What do you want to know? The exact details, math and science behind it can fill entire collage level courses.

But the basic gist is you have a motor with position feedback and a controller that reads the feedback, and adjusts the amount of electricity sent to the motor to maintain the desired position/motion.