V23 RXSM
Supports Bi-directional data (full feature) for Sony/Grass Valley/Hitachi/Panasonic Studio
Supports "Multi Zone" a system to allow multiple ODU transmitters to be used in overlapping areas on multiple frequencies.
Know limitations:
V2 Data support only, therefore IDU should be set: System -> Data Link Version - > V2 (CRC16).
Ikegami and Nac cameras not supported, use 19d
Grass Valley must be set to BiDirectional manually, Camera must be repowered upon selection change. Other makes are automatic. 
The radio firmware should be confirmed up-to-date BEFORE enabling Multizone in system -> Advanced Radio Mode. To do this set the radio to an even multiple of 6.25kHz and then to an odd multiple of 6.25kHz. An example of frequencies to test are 458.6000 and 458.60625. If the radio is up-to date: the "Saving Frequency" should flash up then disappear. If a dotted line appears, do not enable Advanced radio mode.

Correction to Multizone where EEPROM was saving incorrectly
Support for OBTX tester
"Shutter Off" warning removed from Z450