# symbol in structured text of Beckhoff TwinCAT

Hi all,

I've inherited someone else's program and can't for the life of me figure out his use of the # symbol in one of his structured text routines. The usage is essentially as follows:

GUI_flow := int_to_real(flow) / 16#6000 * 200;

He uses this same calculation for the flow rates of various gases used on the tool. What does 16#6000 mean? I figured it was some obscure mathematical operator like modulo or something, but google turned up nothing for me on that front.

Thanks,
Sally

I would have thought it means hex .

Yes, it is hex value.
https://infosys.beckhoff.com/englis...rl_constant_numeric.htm&id=819055798985366477

Thank you so much! I checked the datasheet for the device from which the flow input is coming from and it does list the flow in hex format so it's all making sense now.

Follow-up question, why does 16#6000 have to be hex, but 200 doesn't have to be? Or is it all just for display purposes anyway (i.e. 16#6000 could alternatively just be converted to its 24756 decimal value and written in decimal format instead)?

Doesn't matter. Just more convenient for some constants if the reference for them gives values in Hex. Memory addresses or parameters in drives are often hex based.

Awesome, thank you!