Analog modules   
6.3 Analog  input module SM 331; AI 8 x 16 Bit; (6ES7331-7NF00-0AB0) 
  S7-300 Automation System Module data 
6-8  Manual,  08/2006, A5E00105505-04 
6.3  6.3 Analog input module SM 331; AI 8 x 16 Bit; (6ES7331-7NF00-0AB0) 
Order number 
6ES7331-7NF00-0AB0 
Properties 
●  8 inputs in 4 channel groups 
●  Measuring method adjustable per channel group 
–  Voltage 
–  Current 
●  Resolution adjustable per channel group (15 bits + sign) 
●  Any measuring range selection per channel group 
●  Programmable diagnostics and diagnostic interrupt 
●  Limit value monitoring adjustable for 2 channels 
●  Hardware interrupt can be set when limit exceeded 
●  High-speed refreshing of measured values 
●  Electrically isolated to the CPU 
Resolution 
The measured value's resolution is not dependent on the integration time selected. 
Diagnostics 
For information on diagnostics message consolidated at the "group diagnostics" parameter, 
refer to the table 
Diagnostics messages of analog input modules
. 
Hardware interrupts 
You can set the hardware interrupts of channel groups 0 and 1 in 
STEP 7
. However, always 
set a hardware interrupt only for the first channel of a channel group, i.e. either at channel 0, 
or at channel 2 
High-speed refreshing of measured values 
In high-speed refresh mode, the measured values at two channels of a group occur are 
refreshed three times faster than those at multiple active channel groups. 
Example: Channels 0 and 1 are active with 2 ms filtering. Refreshed data are thus available 
at intervals of 10 ms to the PLC at both channels. (For other settings, the refresh rate is 
equivalent to the filter setting.) 
A high-speed update of measured values is only possible if both channels of channel group 
0 and 1 are active, i.e. the "measuring method" parameter is set. However, only one of the 
two channel groups 0 or 1 may be active (not concurrently active.)