how to create a multiple instance db in step7?

i know how to create an instance db in step7,but when i try to create a multiple instance db for several fbs,i found out that in the dialog box,i could only choose one fb to be referenced.

can anybody help me?thanks!

notfish,

let us suppose the following:

• we have FB1 which controls star-delta switching of a motor
• we have FB2 which the left-right switching of a motor
• we want to do stardelta switching of Motor1, Motor2 and Motor3
• directional control of Motor4 and Motor5 have to be established

Create a new FB, let's say FB3. In the declaration table, put the STAT variables Motor1, Motor2 and Motor3 of type FB1 and Motor3 and Motor4 of type FB2. These are the multiple instances.

In the networks, place the calls to the multiple instances Motor1 to Motor5 and fill the parameters in.

Place a call to FB3 in OB1 and attach a DB to this call. This is the multiple instance DB.

I have attached this project as a zipped external source file, so you don't have to do the typing.

Kind regards,

Jean Pierre Vandecandelaere

you are so kind,jvdcande,i appreciate that.

I m tring to program in S7 very first time. Is it posibel to program object oriented with S7??