Test Mode - Siemens S5-155U System Manual

Coordinator Modes

Test mode

Enabling the test mode with
the 923A
Enabling the test mode with
the 923C
Reaction of the CPUs
6 - 16
Warning
Since, in the test mode, no CPU can emit a BASP (output
inhibit) in the event of a fault, the test mode must be switched
to the inactive state without fail after completion of startup to
avoid a critical or even hazardous system state.
Before you can go into the test mode with the TEST switch, you have
to enable it on the module. This is achieved differently with the 923A
and 923C coordinators.
Insert jumper 3 - 14 on coding socket EP 45 as shown in the following
sketch.
16 14
EP 45
1 3
Set DIL switch S1.3 from Off to On (the following table shows the
DIL switches as delivered; see also Figure 6-2).
DIL S. On Off
S1.1 x
S1.2 x
S1.3 x
S1.4 x
S1.5 x
S1.6 x
When the coordinator mode switch is set from STOP to TEST, the
CPUs can be started individually. There is therefore no synchronized
transition to cyclic program processing. The output of signal BASP is
suppressed on all CPUs, even if there is an error.
If an error occurs with a CPU switched to RUN, only this one goes to
the Stop state in the test mode. The error is indicated by slow flashing
of the CPU's STOP LED. The error at this CPU does not affect other
CPUs.
If the test mode is not activated, a changeover from STOP to TEST
does not result in any reaction of the CPUs.
9
923A Coordinator
8
Effect
–
–

Test mode

No. of occupied CPU slots = 2
No. of occupied CPU slots = 3
No. of occupied CPU slots = 4
System Manual
C79000-B8576-C199-03