Good news: Problem solved!
You were right Old Timer, it was a problem with the resistors. I had configured option [013] to OFF for End-of-Line Resistors, but I had only put the resistors on the empty zones and not on all zones. So I reconfigured [013] to ON (Normally Closed Loops) and I now have my system working.
Now for PCLink, as there is not much information out there on the subject, here is how I have managed to plug to my system with DLS5:
1- First, when you plug PCLink through the USB COM port on your PC, you have to make sure that DLS5 sees it. To do so,
- goto Tools/Modem Manager Configuration
- under Type, select PCLINK and make sure to select USB Serial Port
2- Create a new account
- Note: under Panel Type, you either select your panel model (you will find the panel number on a green tag on your dsc board OR Automatically detect panel (this option did not work for me though, I had to enter the model directly)
3- Open the new account
4- On your DSC keyboard, to allow computer access for a limited time, you do: [*][6][Master Code][5]
5- In DLS5, you select the Global Upload to get all data from the panel, and make sure to select PCLINK as your Connection Type
Data should begin to download. Sometimes it does not and I use the code *[8][Intaller Code][499][Installer Code][499] to force download or upload depending on what I need.
Hope this helps.