According to Epson's site, here are the codes to kick the drawer:
ESC p m t1 t2
[Name] Generate pulse
[Format] ASCII ESC p m t1 t2
Hex 1B 70 m t1 t2
Decimal 27 112 m t1 t2
[Range] m = 0, 1, 48, 49
0 = t1 = 255
0 = t2 = 255
[Description] Outputs the pulse specified by t1 and t2 to connector pin
m to open the cash drawer,
as follows:
· t1 specifies the pulse ON time as [t1 × 2 ms].
· t2 specifies the pulse OFF time as [t2 × 2 ms].