Siemens Simatic S7-300 - Behavior and Diagnostics of the SM 322; DO 8 X 24 VDC;0.5 a; Dependence of the Output Values on the Operating Mode of the CPU and on the Supply Voltage L+ of the SM 322; DO 8 X 24 VDC;0.5 a

Digital Modules
3-77
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
3.23.2 Behavior and Diagnostics of the SM 322; DO 8 x 24 VDC/0.5 A
Effect of operating and mode supply voltage on the output values
The output values of the SM 322; DO 8 x 24 VDC/0.5 A depend on the operating
mode of the CPU and on the supply voltage of the module.
Table 3-19 Dependence of the output values on the operating mode of the CPU and on the
supply voltage L+ of the SM 322; DO 8 x 24 VDC/0.5 A.
CPU Operating State Power Supply L+ to Digital
Module
Output Value of Digital
Module
POWER ON RUN L+ exists CPU value
L+ missing 0 signal
STOP L+ exists Substitute value/last value
(0 signal preset)
L+ missing 0 signal
POWER
OFF
– L+ exists 0 signal
OFF
L+ missing 0 signal
Behavior upon failure of the supply voltage
Failure of the supply voltage of the SM 322; DO 8 x 24 VDC/0.5 A is always
indicated by the SF LED on the module. Furthermore, this information is made
available on the module (entry in diagnosis).
Triggering of the diagnostic interrupt depends on the parameter assignment
(see Section 3.23.3).