My Ademco Lynxr-EN went into alarm mode with a number 29. On reading I see code 26, 27, 28, 29 mean low battery pack but what if just number 29 and it shows alarm not just low battery?

Are we talking about one of the sensors or the system battery...the picture shows the system, so I will attempt to answer that. Based on the pic, the system could have any of several batteries for backup. Looking at the top of the unit, there might be a pull-up drawer in the center, which may contain either a fixed battery (the whole drawer gets replaced) or 6 AA alkalines or 1 9v alkaline or lithium battery. If there is no separate drawer, then you need to push in on the two clips at the sides on top to pop the cover open. The cover is hinged at the bottom and should open relatively freely. Inside you will find a NiMh battery pack. You might be able to get it from Honeywell, your alarm company (if you have one) or have a new pack made at a battery store. Good luck.

The answer above is incorrect. If the back up battery was low it says, "bat" on the screen and that's it. Since the "11" is being displayed, zone #11 on your wireless system as a low battery.

AC is your main power it goes to a transformer that gets pluged in
Bat is your battery power 2 wires going down to your battery

Here http://www.alarmhow.net/manuals/Ademco/Control%20Panels/LynxR/LynxR%20Quick%20Start%20Guide.pdf

and

Here http://www.elitemonitoring.com/docs/pdf/panels/lynxr/LYNXR-ENProgrammingManual.pdf

your access code plus "off"

we need more information than that. Post on diyalarmforum and a tech can talk you through it.

The AC power wires for a Lynx (actually, almost any alarm panel) are from a transformer--there is no "hot and ground". It doesn't matter which wire you put to which terminal, as long as you connect them to the AC connections.

Turn the alarm off two times. If it still indicates A/C not ready, press the * key and it will tell you what zone is open or what zone has a low battery.

yes i can help you who monitors ur system because your gonna need the installer code to get into programming or power down the sytem then hold down the *and # to get into programmming

you have get into programming by disconnecting the power then reapplying it (battery first) within30 seconds press1and 3 ( same time ) until you see 20 flashing. press #20 and the installer code will be displayed one number at a time. If you want to change it press *20and whatever 4 digit code you want the installer code to be. Next Press *99 The system will reset and come out of programming