SWPB command

taylor1982 · Aug 8, 2019

I was using the swap byte command (SWPB) for a long time for swapping REAL values.
Now I have updated an older projekt to Studio5000 V31 and I get a errors prompted at this SWPB command.
For me it seems that they have removed REAL values from the SWPB command.

Is there a way around it?

Thanks
Stefan

travispedley · Aug 8, 2019

COP REAL TO DINT
SWPB DINT
COP DINT TO REAL

I am morbidly curious why you're doing this.

taylor1982 · Aug 8, 2019

travispedley said:
COP REAL TO DINT
SWPB DINT
COP DINT TO REAL

I am morbidly curious why you're doing this.

Thanks but with this I will lose the data after the decimal point right?

I need this to communicate to a PC.

Jonnie_R · Aug 8, 2019

taylor1982 said:
Thanks but with this I will lose the data after the decimal point right?

I need this to communicate to a PC.

You can multiply your real first e.g x 100 if using 2 decimal places then divide the DINT by the same value.

Contr_Conn · Aug 8, 2019

taylor1982 said:
Thanks but with this I will lose the data after the decimal point right?
I need this to communicate to a PC.

No you will not loose any data with COP, it's actually ignoring the value, instead takes a 32-bit pattern from the REAL and puts into the DINT. This is very common when you do comms like Modbus that require a different bit order.

taylor1982 · Aug 8, 2019

Thank you guys for the answers. I will try your suggestions when I´m on site next week.

Have a nice weekend!

taylor1982 · Aug 26, 2019

Just a feedback from my side.
The solution

COP REAL TO DINT
SWPB DINT
COP DINT TO REAL

worked very well. Thanks for your help.

Have a great day!

Stefan

EICS · Aug 26, 2019

is Contr_Conn correct that you are doing modbus comms and changing endian ?

taylor1982 · Aug 26, 2019

EICS said:
is Contr_Conn correct that you are doing modbus comms and changing endian ?

I communicate to a LinuxPC. The LinuxPC has an EthernetIP card installed but interpretes the data in a wrong byte order. Thats why I swaped the bytes on the PLC side.

Till now we used Studio5000 V24 and with this version ist was possible to swap REAL values.

Due to a CPU change it was required to upgrade to V31 and here unfortunately it´s not possible to swap REAL any more.

That´s why I was looking for a work around.

Stefan

HickWand · Mar 24, 2021

taylor1982 said:
Just a feedback from my side.
The solution

COP REAL TO DINT
SWPB DINT
COP DINT TO REAL

worked very well. Thanks for your help.

Have a great day!

Stefan

It worked for me too! Thank you very much

SWPB command

taylor1982

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