Sample Rate I/O Input

Hello everyone,

can someone tell me the sample rate of an analog I/O Input?

Best Regards

Philipp Schiessel

Hello dear friend

1. https://www.plcacademy.com/plc-analog-input-output/ 

2. https://www.contec.com/support/basic-knowledge/daq-control/analog-io/

Hello Philip;

Thanks to Fariboz_M for his links on analog modules, it is important you understand at least the basics of A/D and D/A conversions if you want to know about response times of analog modules.

The next question would be: which module (and CPU family) are you working with? Each module has specific technical data that will influence the "sample rate" and response. Questions such as:

- the type of A/D (for analog inputs) and D/A (for analog outputs) conversion methods have been implemented by Siemens (the manufacturer) in the module? Flash conversion is generally the fastest type, successive approximation value method is often the slowest, integrating will depend on many outside factors but is somewhere in the middle.

- how many channels are active simultaneously on the analog module inside a specific hardware configuration?

- which interference frequency suppression level (signal filtering) has been applied to the input signal?

In the technical data for your specific module you will find basic timing values for analog signal conversion, per channel, depending on the value of these parameters. But they are only a theoretical value, considerations of PLC scan and program load also have an impact.

You can find a lot of information in various Siemens documents. For example, the S7-300 Module Data manual presents analog module information (for the S7-300 family) in chapter 5, specifically in sections 5.4 (Response of the analog modules) and 5.5 (Conversion and cycle times of analog modules); chapter 6 gives the technical data for each S7-300 analog input and output module on the market. Whatever family of processor you are working with, the basic prociples should apply.

S7-300 module data

https://support.industry.siemens.com/cs/ww/en/view/8859629

Look for the technical data of your specific analog module using the search box at the right of this page to find similar information.

Hope this helps,

Daniel Chartier