Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 395)

Chapter 27
The Status File
27–27
Address Description 5/02
5/01,
Fixed
S:16
and
S:17
Test Single Step – Start Step On – Rung/File
Read only. These registers indicate the executable rung (word S:16)
and file (word S:17) number that the processor will execute next when
operating in the Test Single Step mode. To enable this feature, you
must select the Test Single Step option at the time you save your
program.
These values are updated upon completion of every rung (see S:2/4).
Your programming device interrogates this value when providing
“start step on file x, rung y” status line information. There is no known
use for this feature when addressed by your ladder program.
Note: The HHT can save a SLC 5/02 program that has this option
enabled, but the Test Single Step mode is not available with the HHT.
•
S:18
and
S:19
Test Single Step – End Step Before – Rung/File
Read only. These registers indicate the executable rung (word S:18)
and file (word S:19) number that the processor should stop in front of
when executing in the Test Single Step mode. To enable this feature,
you must select the Test Single Step option at the time you save your
program.
If both the rung and file number are 0, the processor will step to the
next rung only; otherwise the processor will continue until it finds a
rung/file equaling the S:18/S:19 value.
The processor stops, then clears S:18 and S:19 when it finds a
match, while remaining in the test single step mode. The processor
will operate indefinitely if it cannot find the end rung/file that you have
entered; it operates until it finds a match, receives a mode change, or
powers down. See S:2/4.
Your programming device interrogates this value when providing “end
step before file x, rung y” status line information. Your programming
device also writes this value when prompting you for “set end rung.”
There is no known use for this feature when addressed by your
ladder program.
Note: The HHT can save a SLC 5/02 program that has this option
enabled, but the Test Single Step mode is not available with the HHT.
•