Power Module Limit

Hi.

Using Siemens configurator I can place the following items.

1.ET-200S IM 151-3 PN 6ES7151-3AA23-0AB0; QTy-01.

2. PM E-24v DC 6ES7 138-4CA01-0AA0; Qty- 01.

3. Total I/O Module:- 12.

But, If I am not wrong in my memory, a Power module can support only 5 I/O Module and after that we need to place another Power Module.

Do you have any practical experience of using power modules or any information about that.

Thanks.