The NI-9237 Specifications
shows that all 10 pins of the RJ-50 connector are used.
RJ-50 to DB-9 cables typically only exposes pins 1 to pins 9, so pin 10, which is responsible for completing the shunt calibration process will not be exposed. If your load cell has a DB-9 connection, you can use the RJ50 to DB-9 cable to connect to the 9237. However, NI recommends using the NI-9949
and an RJ-50 cable for proper pin out connector blocks.