How to tell if DIO is OFFLINE

If I try to read a DI on a device that is OFFLN, my Karel program throws INTP-347 (Read I/O failed) with an underlying cause of PRIO-104 (Device is off-line). I'd like to ignore this error and continue program execution or detect that the device is offline before attempting to read the DI. I already detect if the DI is not assigned using GET_PORT_ASG, which works well.

Is there a way to determine if a DIO device is offline before reading it? Either in Karel or TP code.?

Is there a way to continue execution after receiving this error? I tried using a condition handler but it does not work. Here is the code for that.

CONDITION[OFFLINE_CH]:
  WHEN ERROR[13104] DO 
  WHEN ERROR[12347] DO
    NOMESSAGE
    NOPAUSE
    NOABORT
    CONTINUE
ENDCONDITION
ENABLE CONDITION[OFFLINE_CH]

FOR i = 1 TO DI_COUNT DO
  IF assigned(PORT_TYPE_DI, i) THEN
    dis[i] = DIN[i]  
  ENDIF
ENDFOR

Does anybody have ideas to solve this?

Thanks for the ideas, CSaunders. The first idea is not practical for my case. I'm actually reading all the DIs in a loop to see if any have changed. I tried the UNINIT idea, but it didn't compile.

Fanuc Tech Support gave me the solution. The GET_PORT_VAL Built-In Procedure will return a no-zero status if there is an error, in this case the error is PRIO-104 (Device is off-line).