HEIDENHAIN iTNC 530 HSCI - Data Transfer PLC Operand = NC Program

July 2013 9.5 Data Transfer NC > PLC, PLC > NC 1741
9.5.7 Data transfer PLC operand <=> NC program
READ FROM PLC
KEY
With the READ FROM PLC KEY plain-language command, the value of a symbolic
PLC operand or an absolute address of the currently active PLC program can
be read from within the NC program. The read value is stored in the
transferred Q parameter.
Proceed as follows to enter the READ FROM PLC KEY function on the iTNC 530
HSCI:
 Select the Programming mode of operation
 Select an existing NC program in the file manager or create a new NC
program.
 Enter the MOD code number 555343.
 Press the SPEC FCT key.
 Press the PROGRAM FUNCTIONS soft key.
 Press the PLC FUNCTIONS soft key (fourth level).
 Press the READ FROM PLC soft key.
Command structure:
READ FROM PLC KEY [source] TO [target]
Permissible entries for [source]:
 Symbolic PLC operand or absolute address directly as string, e.g.
"KG_kinematics_active" or "W20"
 Q string as the source of the operand's name, e.g. QS10
Permissible entries for [target]:
 Q parameter, e.g.:Q10
 Q parameter reference, e.g.:Q REF Q10
 Q string, e.g.:QS10
 Q string reference, e.g.:QS REF Q10
 QL and QR parameters, e.g.:QL499
The type of the Q parameter specified in [target] must match the
interrogated PLC operand. The control will otherwise issue the error message
Access to PLC variable has failed.
Note
The READ FROM PLC KEY command is run in look-ahead, meaning that the
control executes the command immediately instead of waiting until the NC
program has been executed up to the corresponding point. If a
synchronization with real time is necessary, then FN20: WAIT FOR SYNC
must be programmed in the preceding NC block. Look-ahead is then
stopped, and READ FROM PLC KEY is not performed until this block is actually
reached in the NC program.