I'm confused about "zapping" and buying tickets to/from Sintra from Rossio station. If you have a charged up Viva Viagem card, do you still stand in line to buy tickets at Rossio station? Can you buy the tickets the day before? Are they paper tickets or e-tickets? Are the tickets for specific dates, specific trains? Any specifics are appreciated. Can you buy tickets online from the Comboios de Portugal web site?
I was also confused about this “zapping” Viva Viagem Card before visiting Lisbon.
We bought our Viva Viagem cards at a ticket machine, at the airport, then took the Metro to Oriente station and the train to Sintra.
On a separate day, we took the train from Lisbon to Cascais and it was great to just board the train and avoid the long ticket lines at Cais Do Sodre Station.
When we arrived to Cascais, my daughter wasn’t able to exit the station (through the turnstile) because her card had become deactivated. I had to get a train station staff member to help with this situation. Apparently her card had become deactivated because she had been carrying it next to her cell phone!
Enjoy your trip!