Siemens Simatic S7-400 - Manual (Page 282)

Analog Modules
5-66
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Table 5-47 Diagnostics Messages of the Analog Input Modules, Causes of Errors and Remedial
Measures, continued
Diagnostics
Message
Remedy Possible Error Cause
EPROM error The module is defective Replace module
RAM error
ADC/DAC error
Hardware interrupt lost The module cannot send an
interrupt, since the previous
interrupt was not acknowledged;
configuration error possible Change interrupt handling in the CPU
(change priority for interrupt OB; shorten
interrupt program)
Configuring/parameter
i t
Illegal parameters transferred to
d l
Check measuring range module
assignment error module
Reassign module parameter
Short circuit to M A short circuit to the M potential has
occurred on the sensor supply of
two-wire transmitters Eliminate short circuit
Wire break Resistance too high in the sensor
connection Use different type of sensor or
connection, e.g. use conductors with a
larger cross-sectional core area
Open circuit between module and
sensor Close circuit
Channel not connected (open) Disable channel (“Measuring Type”
parameter)
Connect channel
Reference channel
error The reference junction connected at
channel 0 is faulty due to a wire
break, for example Check terminals
The reference temperature value
transferred is not within the value
range Reparameterize the reference
temperature
Underflow Input value violates underrange,
error may be caused:
Wrong measuring range selected
Configure other measuring range
With the measuring ranges 4 to
20 mA and 1 to 5 V, if necessary by
polarity reversal of sensor
connection Check terminals
Overflow Input value overflows overrange Configure other measuring range
Run time calibration
error A wiring fault has occurred on a
channel during the calibration cycle Eliminate the wiring fault (fault remains
until the next calibration; in other words,
a maximum 6 minutes or until there is a
STOP-RUN transition of the CPU)