Siemens S7-300 Installation And Operating Manual page 216

Analog modules
9.2 SM 336; AI 6 x 13 Bit
Causes of the problem and corrective measures
The table below shows possible causes of the problem and appropriate corrective measures
for the individual diagnostic messages of SM 336; AI 6 x 13Bit.
Table 9- 12
Wire break (only in the 4 to
20 mA measuring range)
Discrepancy error
Common mode fault
Overflow or underflow of the
measured value (see "Wire
break and underflow") in
Chapter "Analog value
representation (Page 182)")
Incorrect module parameters Faulty parameters transferred to
Parameter assignment error
(with specification of a
consecutive number; for
example, "16": incorrect
address)
ADC/DAC error
No external auxiliary voltage
216
Diagnostic messages and associated corrective measures for SM 336; AI 6 x 13Bit
Diagnostic message Possible causes of the problem
Interruption of the measuring lead
between the module and sensor
Incorrect measuring range setting
Assigned tolerance window
exceeded on expiration of the
discrepancy time
Wire break
Deviation between two inputs
outside limits of safety mode to
SIL 2
Potential difference U between
CM
the inputs (M-) and reference
potential of measuring circuit
(M ) too high.
ANA
Measuring range fallen below
Measuring range exceeded
Current through sensor too high at
startup
module
Error in dynamic parameter
reassignment
Internal error during analog value
test
Internal voltage monitoring has
reported a fault
Module supply voltage L+ missing
Installation and Operating Manual, 01/2010, A5E00085586-10
Corrective measures
Reestablish the cable connection
Set the 4 to 20 mA measuring
range
Extend the tolerance window
and/or discrepancy window
Eliminate the wire break Check
the process signal.
Wiring error: wire the analog
signal to both inputs, or replace
the module
Interconnect M- with M
ANA
Use a suitable sensor; check the
wiring (sensor polarity reversed)
Use a suitable sensor; sensor
polarity reversed
—
Assign new module parameters
Check the parameter assignment
in the user program
Contact SIMATIC Customer
Support if necessary
Replace the module
Connect supply voltage L+
Fail-safe signal modules