I don't know anything about that motor, and I have only just started to familiarize myself with EMC2.
Having said that, though, if your immediate goal is to find out what the step angle is, an easy way to do that would be to throw together a simple, slow repetition-rate pulse generator, and apply the signal from the pulse generator to the step input of your motor driver, then just count the steps for a full revolution of the motor shaft.
For example, Gecko has published a simple step and direction pulse generator circuit that could probably be adapted easily enough for your use (I'm not sure what the pulse rate is or how slow it could be made to go - and you might want to add an LED to indicate each pulse occurrence, or a debounced momentary contact step switch to do manual pulsing).
See the following Gecko support page for the circuit: Support
If you are able to single-step the motor using a jog mode of EMC2, then you wouldn't even need to build such a circuit to accomplish your goal.