Why do my wireless sensors work, but my key fobs don't?

In a wireless system, whether in a L5200 or L7000,  panel or a Vista-15P, Vista-20P, or Vista-21iP, you may find that your wireless protection points are working, but your key fobs are not.  There can be a couple of different reasons for this.  In most newer systems, including those listed above, a keyfob must be assigned to a valid user code before it can be used to arm or disarm the system.  An easy way to test if this is the issue is, if you have a panic zone programmed onto one of the buttons on the fob, test this button by pressing and holding it for 2 seconds then releasing.  Panic zones on fobs will work regardless whether the fob is assigned to a user code or not.  If you test the panic and it works, you know you need to assign the rest of your fob to a user code so that you can arm or disarm with it.  The way in which you assign a key fob to a user code varies between the Lynx panels and the Vista panels.  

If you try this test, and the programmed panic does NOT activate the system, or if all the other devices on the system are working, but the key fobs are not, the likely culprit is encryption.  Most key fobs are capable of encryption, while some actually require it.  Some 2 or 4 button keyfob with an EN at the end of the part number MUST be used in conjunction with an Encryption capable receiver such as the 5881ENH with Encryption enabled.  In addition to this, there is a procedure you must follow which will sync the key fob to the receiver (see instructions for the key fob model you have) in order to make this work.  If you try to use one of these Encryption-only fobs with a receiver that doesn't support Encryption, it will never work.  All LynxTouch panels support the use of Encryption. The 6150RF and 6160RF both have a programming option to enable or disable High Security Encryption.  If this programming option does not match the setting for the key fob, then the key fob will never work.  Some older 5881 style receivers had a dip switch, dip switch 1, that had to be ON for encryption to be enabled.  If the dip switch was on, but the fob was not programmed properly for Encryption, then it would never work.  There are numerous ways for this to go wrong, so just remember, when it comes to Encryption, the receiver and the key fob must be programmed to match, or the key fob will not work.