Verify if DSP01 was somehow renamed to DSP02:
WRKDEVD DSP0* to list all
If only DSP02 exist, take option 5 to display the Port number and Switch setting. Both will be 0 if it was DSP01 in which case you can take option 7 and rename it back to DSP01.
If both settings are not 0, then recreate DSP01.