Siemens Simatic S7-400 - Manual (Page 248)

Analog Modules
5-32
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Behavior on Failure of the Supply Voltage
Failure of the load power supply L+ of the diagnostics-capable analog module is
indicated in the case of parameterized two-wire transmitters by the EXTF LED on
the module. Furthermore, this information is made available on the module (entry in
diagnostic buffer).
Triggering of a diagnostic interrupt depends on the parameter assignment (see
Section 5.7).
5.5.2 Effect of Range of Values of the Analog Values
Effect of Errors on Analog Modules with Diagnostics Capability
Any errors that occur can lead to a diagnostics entry and a diagnostic interrupt with
analog modules with diagnostics capability and corresponding parameter
assignment. You will find the errors that might be involved in Section 5.16.
Effect of Range of Values on the Analog Input Module
The behavior of the analog modules depends on where the input values lie within
the range of values.
Table 5-39 Behavior of the Analog Input Modules as a Function of the Position of the
Analog Value Within the Range of Values
Measured
Value In
Input Value LED
(EXTF)
Diagnostics Interrupt
Rated range Measured
value – – –
Overrange/
underrange Measured
value – – –
Overflow 7FFFH Flashes 1 Entered 1 Diagnostic
interrupt
1
Underflow 8000H Flashes 1 Entered 1 Diagnostic
interrupt
1
Beyond the
programmed
limit Measured
value – – Hardware interrupt 1
1) Only for modules with diagnostics capability and depending on parameter assignment