I've configured a TP900 in TIA Portal V13.
The tags in the project are coupled with a S7-315 CPU that is configured in Step 7.
When I try to simulate the HMI in TIA Portal, no tags are linked. 

How can I fix this?

Hello KGI,

What connection did you program between HMI and PLC?

How is PG/PC interface defined?

Best regards,

Wizard

KGI

I've configured a TP900 in TIA Portal V13.
The tags in the project are coupled with a S7-315 CPU that is configured in Step 7.
When I try to simulate the HMI in TIA Portal, no tags are linked. 

How can I fix this?

 HI

Try use absolute address (like: M0.0, ... not symbol tag), in connection choose s7300 driver, right slot, rack

KGI

I've configured a TP900 in TIA Portal V13.
The tags in the project are coupled with a S7-315 CPU that is configured in Step 7.
When I try to simulate the HMI in TIA Portal, no tags are linked. 

How can I fix this?

Do you hope to simulate..
1. a simulaed HMI with a simulated CPU
2. a simulated HMI linked to an actual CPU
3. a simulated HMI as-is with direct control over tags

For options 1 and 2 - answer Wizard's post.

For option 3:    (just to start your journey)
a) Select the HMI project (in my case the KTP700)

b) Simulate with tags