Siemens S7 PID Reset input format

Andy32821

Member
Join Date
Aug 2003
Location
Orlando
Posts
5
I am to writing a floating point number for PID “reset time” from a SCADA HMI to a data block register in a S7-400 processor simatic PLC. Contrary to some published data I cannot get the PID block to read milliseconds. The PID block seems to insist that the reset and rate times be in siemens’ “time format” data type before the PID block will read them.

Can I force the PID block to accept milliseconds?

Is there a math block that will convert decimal into time format?


Thanks, Andy
 
S5-Timer-format for preset-variable

15.............0 = timer preset
bits 15,14,13,12 are the time-base bits
xx00=timebase 10 ms
xx01=timebase 100 ms
xx10=timebase 1 second
xx11=timebase 10 second
bits 0 to 11 are for preset in BCD format, so max is 999

In 'Program elements/ Standard Library/ S5-S7 Converting Blocks'
have FC62 for Float to Fix Converting.
Also you need Fix to BCD convert-command.
You must check value and 'time-base' and try convert that to
S5-Timer-format

Are there tools in Scada for this , scripting ?
 
Last edited:
Thanks for the reply. I think I had better keep this part in the PLC. I was hoping siemens had something a little more elegant since this must be a common tast to programers. Maybe I will try the S7 scripting and see if it"s code is less messy than the ladder blocks.
 
Last edited:

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