Siemens Simatic S7-300 - Diagnostics of the Analog Modules

Analog Modules
4-71
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
M
L+
Backplane
bus
DAC
R
L
Q
I
M
ANA
M
internal
L+
M
Ground bus
CPU
Logic
Figure 4-31 Connecting Loads to a Current Output of a Non-Isolated AO
4.16 Diagnostics of the Analog Modules
Programmable and Non-Programmable Diagnostic Messages
In diagnostics, we make a distinction between programmable and
non-programmable diagnostic messages.
You obtain programmable diagnostic messages only if you have enabled
diagnostics by parameter assignment. You perform parameter assignment in the
“Diagnostics” parameter field in STEP 7 (refer to Section 4.7).
Non-programmable diagnostic messages are always made available by the analog
module irrespective of diagnostics being enabled.
Actions following diagnostic message in STEP 7
Each diagnostic message leads to the following actions:
• The diagnostic message is entered in the diagnosis of the analog module and
forwarded to the CPU.
• The error LED on the analog module lights.
• If you have programmed “Enable Diagnostic Interrupt” with STEP 7, a
diagnostic interrupt is triggered and OB 82 is called (refer to Section 4.17).