KUKA KRC1 $DATE.HOUR: Resolving Component Access Error

On a KUKA KRC1 running KSS V4.1.7 SP08, direct access to $DATE.HOUR can produce the message Access to component inadmissible. Copy the complete $DATE structure into a declared DATE variable, then read the Hour component from that copy.

Identify the KRC1 access failure

The failing SPS logic accesses a component of the system variable directly:

IF ($DATE.HOUR==0) THEN
  I[2]=I[1]
  I[1]=0
ENDIF

This direct form is reported to work on KRC4, but KSS V4.1.7 SP08 on KRC1 rejects it. The evidence also reports successful direct access on a KRC2 running KSS 5.6.6, so do not treat the KRC1 result as behavior shared by every KSS generation.

Copy $DATE before selecting Hour

Declare a variable with the DATE data type, assign the complete system date structure to it, and access the component through the local copy:

DECL DATE _Date
_Date = $DATE

IF (_Date.Hour == 0) THEN
  I[2]=I[1]
  I[1]=0
ENDIF

The confirmed workaround changes only the access path: $DATE supplies the complete structure, while _Date.Hour supplies the hour value used by the condition.

Apply and verify the workaround

1. Replace the direct $DATE.HOUR reference with a declared DATE variable.
2. Assign $DATE to that variable before evaluating its Hour component.
3. Confirm that KSS accepts the code without Access to component inadmissible.
4. Verify that the intended assignments execute when _Date.Hour equals 0.

This evidence confirms the workaround for KRC1 with KSS V4.1.7 SP08. It does not establish which internal compiler or system-variable restriction causes the direct component-access failure.

FAQ