Siemens SIMATIC VPU200/560 Programming Manual page 86

When the spacebar is pressed, the function keys shown above will disappear
and will be replaced by a single operation over the F1 function key. This
operation is the "NEXT INSTRUCTION" and it will find the next non-NOP
rung of ladder logic.
NOTE: Use the "NEXT INSTRUCTION" function key with care. If you press
this function key when the bottom of a program is displayed, the system will
look through the remainder of configured memory for the next instruction.
If you have a large amount of memory configured and the system is in the
Online mode, this could take a long time. Also, once the function key is
pressed and the system begins searching, there are no keys on the VPU200
to halt the search.
The remaining function keys are used to find particular I/O elements,
words, or box operations in the rungs of ladder logic. "CPWDS" is used to
find the variables for the current and preset values of drums, counters, and
timers; "OUTPUT" is used to find an end, jump, skip forward, label, or
master control relay; "BOX" allows you to locate box operations; "WORD" is
used to locate word variables; and "BITIO" allows you to find X, Y, and C
contacts and coils.
To locate an element, press the function key for the desired category. This
will bring a second menu to the screen. Press the function key for the
particular element you wish to find. Next, type the identifying number for
the element on the prompt line. (Note that to find a DCP value you must
type both the number of the drum and the number of the step. The first
prompt which appears on the screen will be for the drum; to enter the
number for the step, press the right arrow key. This will place the prompt
for the step on the screen. You may return to the previous prompt by
pressing the left arrow key.) Finally, press the Return key to start the FIND
operation. Note that if you wish to find a box operation and you are unsure
of the identifying number for it, type a zero for the identifying number. This
will then find the next occurrence of the box operation (after the Return key
is pressed) and you may continue to press the Return key until the sought
box operation is found. When the sought element is found, it is displayed. To
quit the FIND operation, you must press the ABORT (F1) function key.
SIMATIC VPU200/560 Programming Manual Entering Ladder Programs 8-17