ll be set to zero.
datamode = "CPLHIST"
  Reads in data from coupler history files generated by a previous run 
datamode = DIATREN_ANN_RX1,DIATREN_IAF_RX1
  Reads in annual and intra-annual forcing runoff data used for CORE2 forcing runs
  Only valid for rof mode

Set by the following xml variables in env_run.xml
DROF_MODE 
   specifies values for rof mode: CPLHIST,DIATREN_ANN_RX1,DIATREN_IAF_RX1,NULL
   default value: DIATREN_ANN_RX1
</pre>
        </div>
    </td>
    <td>char*256</td>
    <td>shr_strdata