Forcing Outputs, "Force", For Cpu 103 And Higher; Forcing Variables, "Force Var - Siemens S5-100U User Manual

Start-up and Program Tests
4.7

Forcing Outputs, "FORCE", for CPU 103 and Higher

Outputs can be set directly to a desired status even without the control program. This enables you
to control the wiring and functionality of output modules. This does not change the process I/O
image table, but the output disable condition is cancelled.
Note
The programmable controller must be in the STOP operating mode.
Refer to your programmer manual for information about calling up the test function on your
programmer.
4.8

Forcing Variables, "FORCE VAR"

The process image I/O table of the operands is changed regardless of the programmable controller's
operating mode. You can change the following variables: I, Q, F, T, C, and D.
The program is processed in the RUN operating mode using the changed process variables. They
can be changed again during program scanning without an acknowledgement being required. The
process variables are forced asynchronously to the program scanning.
Special characteristics
• You can change the I, Q, and F variables in the process I/O image table by bits, bytes, or words.
• For the T and C variables in KM and KH format, note the following:
- For programmers with screens, you must also enter "YES" in the system commands input
field in the presettings screen.
- You must be careful when you force edge trigger flags. You do not want to enable a higher-
order byte inadvertently because this could give you a timer or counter value you did not set.
• The signal status display breaks off if there is an error in the format entry or operand entry. The
programmer then displays the "NO FORCING POSSIBLE" message.
Refer to your programmer manual for information about the test function on your programmer.
4-10
S5-100U
EWA 4NEB 812 6120-02