I am looking for a 2kHz ADC on a PLC.   The sample frequency is required to be close to and over 2kHz.   Can the S7 1500 do this.   On the data sheet I same a sample rate of 4ms.   Which puts our sample rate into 250 hz.    Am I reading the wrong value.    I know NI does projects that reach this.   However, we are trying to move to a PLC.

Regards

Easily.

You have two options:

• a remote IO on Profinet IRT with 500 us bus cycle
• an IO module with oversampling in a rack (AFAIK backplane is limited to 1 ms cycle)

Thanks for the suggestion

Would the S7 1500 be the right architecture or do I need to move to the S7 300.

Regards

Use S7-1500.

A few options, but they involve at least the following:
s7-1517 or s7-1518
Network topology defined (which allows ISO/IRT)
Remote IO
HS/HF Analog input module on remote IO
ISO/IRT enabled and configured for required data rate
SYNC_PI called via OB3x timed / cyclic interrupt OB at the required sample frequency

If you need to send that data, I suggest UDP because it is very fast and can be tricked into sending data every OB3x call.

With this approach, you can achieve 5000 Hz on S7-1518 and 2500 Hz (max) on S7-1517

With a lower level S7-1500 PLC, you can BATCH update using the HF modules which allow capturing multiple analog values and sending out all at once.

If this is too complicated and inappropriate or expensive, you can save cost by wiring these to an NI board and using your existing data capture methods.

For your first high speed PLC project, note that virtually everything else in the PN network will try to interfere with your high speed PN / ISO/IRT data communications, be it some incompatible firmware revision, some little nuance that prevents a device from fully participating at that data rate unless it is the very last or very first PN node, or some other odd reason Siemens will never admit to fault on - at least while your project is progressing.  About 3-6 months after you find a work-around, they will finally come back and admit fault with an external vendor's firmware being incompatible (despite the fact they likely were the external vendor's firmware author).

AlleyCat78

I am looking for a 2kHz ADC on a PLC.   The sample frequency is required to be close to and over 2kHz.   Can the S7 1500 do this.   On the data sheet I same a sample rate of 4ms.   Which puts our sample rate into 250 hz.    Am I reading the wrong value.    I know NI does projects that reach this.   However, we are trying to move to a PLC.

Regards

You may find following links interesting:

High-performance measurement technology in PROFINET environment

SIMATIC S7-1500 Isochronous mode

S7-1500/ET 200MP Analog Input Module AI 8xU/I HS

Expanded functions for the High Feature (HF) and High Speed (HS) analog modules