Siemens SIMATIC User Manual

Digital modules
3.11 Digital input module SM 321; DI 16 x 24 VDC; with hardware and diagnostic interrupts (6ES7321-7BH01-0AB0)
S7-300 Module data
Manual, 06/2017, A5E00105505-AJ
89
Note
Wire break diagnostics
Wire break diagnostics is always used for one channel group with two channels. It is only
possible to determine that one of the two channels has suffered
a wire break; it is not
possible to identify which one. When operated with PCS7, only one channel of the group can
be used at any time for an exact diagnosis.
Causes of error and troubleshooting
Table 3- 14 Diagnostics Messages of the SM 321; DI 16 x DC 24 V, causes of error and troubleshooting
Diagnostic message
Possible cause of error
To correct or avoid error
Sensor supply missing
Overload at sensor supply
Eliminate overload
Short-circuit to M at sensor supply
Eliminate the short-circuit
External auxiliary voltage
missing
Power supply L+ to module missing Feed supply L+
Internal auxiliary voltage
missing
Power supply L+ to module missing
Feed supply L+
Fuse blown in module
Replace the module
Fuse blown
Fuse blown in module
Replace the module
Incorrect module parame-
ters
Implausible parameter or combination thereof Program the module
Watchdog timeout
Infrequent high electromagnetic interference
Eliminate the interference
Module defective
Replace the module
EPROM fault Infrequent high electromagnetic interference Eliminate interference and cycle the power
supply of CPU off/on.
Module defective
Replace the module
RAM fault Infrequent high electromagnetic interference Eliminate interference and cycle the power
supply of CPU off/on.
Module defective
Replace the module
Hardware interrupt lost The module can not output an interrupt, be-
cause the previous interrupt was not
acknowledged; possibly a configuration error
Change interrupt processing in the CPU, and
reprogram the module as required
The error persists until the module is assigned
new parameters
Module not programmed
Startup error
Program the module

Siemens SIMATIC Specifications

General

Product type designation	SIMATIC
CPU	Varies by model
Memory	Varies by model
Input/Output	Varies by model
Communication	Varies by model
Programming Language	STEP 7
Operating Temperature	0°C to 60°C (varies by model)
Protection Class	IP20
Category	Programmable Logic Controller (PLC)