When you are setting up a Concord 4 GSM and you are getting one flash on LED 1 this means the panel is having trouble communicating with the GSM. Try the steps below to try and jump start the communication between the panel and the GSM.
1.) Power Cycle the panel
2.) Perform a Comm Test (8+Installer Code+3)
3.) Then enter (Disarm+ Installer Code)
If it does not work the first time try performing steps 2 and 3 again. If the problem still persist please contact Safemart Technical Support.