With the USB, SDI and NDI native models (the 12X-NDI, 20X-NDI, 30X-NDI), you should be able to get the network stream up to 60FPS. If you are not able to do this, you may have to update the cameras to the latest Firmware version which can be found HERE.
The only PTZ optics cameras that do not support 60FPS over IP (NDI, RTSP, RTMP) are the first generation cameras and the Z or box cams (PT12X-Zcam, PT12X-NDI Zcam, PT20X-Zcam, PT20X-NDI-Zcam, PTVL-Zcam, and PTVL-NDI-Zcam).
This is a hardware limitation and can not be fixed with a firmware update and will not be available until a later generation.
edited 02/21/2019 SR