I have seen a couple of places where a the time on a Toff timer is coming from a HMI parameter page where the user (with the right authority) can type it in. This value is then stored in a DB in the form of a DBW. The DBW is then used as Toff time on the timer.

My question is - will the Toff interpret this time as seconds (my guess), milliseconds, minutes or something else?

If it's IEC timer, then miliseconds.

If it's S7 timer, then time base is in the setpoint. Check in onlime manual "S5time" to see how it is done.

Thank you for answering jacek d.

Please also see the attached  screenshot.

The timer itself is "wrapped" into a know-how protected block so I cannot see it but when the PT input has an initial value of T#0MS I am thinking the value is in milliseconds - so that I have to write 1000 for one second off delay - or how should it be read?

jacek d

If it's IEC timer, then miliseconds.

If it's S7 timer, then time base is in the setpoint. Check in onlime manual "S5time" to see how it is done.

Well, for sure the input of the timer is in a TIME datatype. Which means it's 32 bit signed integer value in milliseconds.

But whatever is entered on the HMI, can be scaled to match this. E.g. you can enter 1.1 in seconds, then it is scaled to milliseconds 1100.0 and then cast to integer 1100 and finaly written to a PLC.

To get idea what is going on - enter a value (but not 0) on the HMI and then check what is written to the PLC.

Thanks for answering again jacek d.

Yes - that was (and is) my plan.

I had just hoped I could see it from the logic alone without needing to go online.

jacek d

Well, for sure the input of the timer is in a TIME datatype. Which means it's 32 bit signed integer value in milliseconds.

But whatever is entered on the HMI, can be scaled to match this. E.g. you can enter 1.1 in seconds, then it is scaled to milliseconds 1100.0 and then cast to integer 1100 and finaly written to a PLC.

To get idea what is going on - enter a value (but not 0) on the HMI and then check what is written to the PLC.

 Hi again jacek d,

I do have access to both those things - but how can I see it there?

In  the HMI display the number is entered in an I/O field - and I can see in the Tag manager that is is written into the mentioned DB1202,DD418 = DB1202.DBD418 = SP121 (TIME T#0MS Tid for autostop af drejeskive).

But this is just a number without a unit. Big difference if it is milliseconds or hours.

jacek d

If you have access to the HMI project and its engineering software, you could check it there.

What brand is your HMI?

In case of WinCC flexible, for example, a tag has properties. And one of them is scaling.

The brand is Siemens. The SW version is WinCC 7.4.

Where is WinCC 7.4 is the scaling?

Is it in the Graphics Designer or perhaps in the Tag Manager?

Please also see the screenshots.

jacek d

What brand is your HMI?

In case of WinCC flexible, for example, a tag has properties. And one of them is scaling.

Long time since I messed up with WinCC...

I'd check Tag Management. Find the tag and try to find its properties menu. Right click maybe?