Siemens S5-155U System Manual page 410

The 463 Analog Input Module
Enable input
Switching off the enable input
9 - 38
The enable circuit requires an external 24 V voltage at enable inputs
F+/F- in the front connector. If there is no voltage at F+/F-, the
modules will not acknowledge.
When the front connector is swivelled away from the front strip of the
module, the supply of power to the enable input is interrupted, i.e. the
module is switched off and can no longer be addressed by the user
program: a timeout (QVZ) occurs in the CC.
The -4Ux12 type modules additionally offer the facility for changing
the enable mode. The modules have a jumper accessible from above in
the vicinity of the addressing switch.
Enable Jumper
Figure 9-13 Enable Input and Enable Jumper
Jumper inserted: Enable input (F+/F-) active (factory setting)
Jumper open: Enable input (F+/F-) switched off
Examples of functioning of the enable inputs:
• • To switch off individual subprocesses, i.e. outputs of various
modules can be operated from a common load supply and yet
activated separately.
• • The load voltage of individual modules can be monitored without
additional circuitry. Any reactions to failure of the load voltage
can be programmed in the QVZ (timeout) organization block.
System Manual
C79000-B8576-C109-03