Diagnostics Of Digital Modules - Siemens SIMATIC Manual

3.4

Diagnostics of digital modules

Introduction
The information provided in this chapter applies only to S7-300 digital modules with
diagnostics functions.
● Digital input module SM 321; DI 16 x DC 24 V with process and diagnostic interrupts,
isochronous; (6ES7321-7BH01-0AB0)
● Digital input module SM 321; DI 16 x DC 24 V/125 V with process and diagnostic
interrupts (6ES7321-7EH00-0AB0)
● Digital output module SM 322; DO 16 × UC 24/48 V (6ES7322-5GH00-0AB0)
● Digital output module SM 322; DO 16 x DC 24 V/0,5 A (6ES7322-8BH10-0AB0)
● Digital output module SM 322; DO 8 x DC 24 V/0,5 A with diagnostic interrupt
(6ES7322-8BF00-0AB0)
● Digital output module SM 322; DO 8 x AC120/230 V /2A ISOL (6ES7322-5FF00-0AB0)
● Digital output module SM 322; DO 8 x Rel. AC230V /5A (6ES7322-5HF00-0AB0)
Programmable and non-programmable diagnostics messages
We distinguish between programmable and non-programmable diagnostics messages.
You only obtain programmable diagnostics messages if you have enabled diagnostics at the
relevant parameters. Program the "Diagnostics" parameter block in STEP 7.
Digital modules always return non-programmable diagnostics messages, irrespective of
diagnostics being enabled.
Reactions to diagnostics message in STEP 7
Actions initiated by diagnostics messages:
● The diagnostics message will be entered in the diagnostics data of the digital module,
and is then passed to the CPU.
● The SF LED on the digital module is lit.
● When "Enable Diagnostics Interrupt" is set in STEP 7, the system triggers a diagnostics
interrupt and calls OB82.
Reading diagnostics messages
You can read detailed diagnostics messages using SFCs in the user program (refer to the
appendix Diagnostics data of signal modules (Page 583)).
In STEP 7, you can view the cause of error by reading the module diagnostics data (refer to
the STEP 7 Online Help.)
S7-300 Module data
Manual, 06/2017, A5E00105505-AJ
Digital modules
3.4 Diagnostics of digital modules
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