Input devices are specified as the components of a bit mask, as described in Input Devices of a Device Group. The following function activates input devices:
void dvc_set_inp_mask(unsigned device_mask)
This function enables and disables input devices. Each input device corresponds to one bit in the device mask. Input device 0 corresponds to the keyboard.
For example if KEYBOARD=1,SCANNER=2 and MSR=4 then an input device mask of 3 enables KEYBOARD and SCANNER but disables MSR.It is good practice to follow the example of PROGRUN and explicitly enable input before each field, and to set the input mask to 0 again once input in a field is completed. This makes it much easier for the OSDI to be sure that data from devices such as bar code readers is being read correctly.