UDT in S7-400 environment

Hi Expert house,

We are using for valve feedback time out defined in UDTs. There are two time settings TD0 and TD1.

We have at least 50-60 valves of various types like Diverter valve, flap valve etc.. with separate UDTs

My question is if I wish to change the time in UDT. What is the procedure.

1) Go ONLINE with PLC and change in UDT

2) Then shall open individual valve blocks where this UDT is used. In fact each valve block has called block FC117 where this times are used.. So is it OK if just I open FC117 and save it.

OR

any download of FC117 is envisaged.

Next question is that if by any reason I want to affect these time changes in only one valve block but not all, is there a way. If valve feed back error bit is forced (it is "M" type in logic) will it avoid trip

Thanks in advance

Vijay

Hi Vijay,

UDT is like FC - structure without memory. DB considers it as one kind of data type. When u declare UDT as data type in DB, structured memory will be formed. 

1. If u make changes in UDT, it will be executed in all instances[wherever in DB it is used]. Also u need to update DB/FC for UDT modifications. Simplest way is to use VAT. Manually add all timer addresses and monitor/modify.

2. If u wish to give different values to timer registers, it is also possible. Open the DB in offline folder. Go for data view-Ctrl+4. Now write desired values in actual values column and save and download.[ Do not initialize data block].