IO, reading Group output // big endianness PLC ( siemens s7 1200 )

Robot Controller
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1

Hi,

I’m fairly new to Profinet / PLC programming.
We’re working on integrating with a s7 1200 PLC, which has big endianess, whereas IRC5 has little endianness.
One way is to resolve this through the READ_LITTLE cmd in the PLC’s SCL language.

This means effectively “shadowing” your remote IO / signals read over Profinet.
Is there a better way / is this a correct or elegant way of handling this (AFAIK there is no way to control the endianness of IO)?
I realize the Siemens s7 1500 does support little endianness, so perhaps this is more painless / worth the extra cost.

2

Define your robot group signals mapping different way. e.g. instead of mapping 0-15 use mapping 8-15,0-7. This is how I do it.

Mika

3

I just tried it in robotstudio, Map your signals backwards from how we usually do it. Instead of 0-7 and 8-15 for two, eight bit groups, do 7-0 and 15-8. I think that may have been what msalminen was trying to say.

4

Gents, many thanks to both of you, that helps a huge deal…