I have a hotel with a Hospitality G3r - the PMS link is down. The existing data module is a 7400B. I've ordered a 7400A Data Module and I'm thinking I should order a TN577 as well. 2 questions: will the 7400A work with a G3r PMS link? Also, when the TN577 is replaced, is there any programming that must be done? This setup has been working for years. PMS vendor is working with us. Thanks!