G120 S7-1500 Read Write IO Telegram Best Practice

Hi All,

I am busy writing a new FB to interface S7-1500 with G120 drives. In this particular case I am using TIA V16/17, with G120 drives fitted with CU240E-2 PN Control Unit ... so on Profinet.

But my question is more general. I was looking to see how Siemens recommends to do the reading/writing of the I/O ... but I could not find much in the G120 manuals.

I understand the telegram setup etc. but what I was wondering is how best to read/write. I see at least 3 methods

1. DPRD_DAT / DPWR_DAT

2. GETIO / SETIO

3. PEEK / POKE

The downloaded examples all seem to use DP**_DAT. This includes the SINA_SPEED extended library block.

But doing research on the forum it seems that some feel that these blocks add overhead / execution time and are unnecessary.

Then I noticed some like to use GETIO/SETIO .... and in the past I sometimes used PEEK/POKE

One difference would be the HW identifier which could make the block more portable using certain instructions.

Also I do want to write a custom block as I want customise the telegram. 

But in general ..

    Is there any clear advantage / disadvantage using one method over another ?

Thanks

I am not an absolute expert on that SIMATIC functions but I heard it is recommended to use GETIO / SETIO to read and write the cyclic telegram data for the drive. Those functions are intended to be used with the new PLCs in TIA Portal. I heard that DPRD_DAT and DPWR_DAT are more or less the ones from the "old" SIMATIC world and just exist for compatibility reasons.

So I always used GETIO / SETIO which always worked fine for me with SIMATIC and SINAMICS communication. 

Closed cause question posted twice.

The second thread with the subject I/O Access on Profinet - Best Practice is published within the conference Communication / Networks.

Best regards,
Jen_Moderator
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