Electrics: 70: fault code meaning

[JD.7]

today my 98 V70 R was dead battery wise there was no life in it at all.

i called the RAC out and the volt reading was .9v them 2 mins later 1.0v. the RAC man boosted the battery and the alarm went off , the remote would not stop it so i started the car ( with the alarm going off ). the alarm would keep going off and resetting itself. in the end the battery was disconnected then re connected , when the key was put in the ignition and the car started the alarm stopped.
i fault code read it and got...GLA-311 siren faulty signal...
the engine was turned off after 10 mins and the battery was tested to find the RAC tester telling the mechanic the battery was no good , the batter is 1 year 2 days old and is a Volvo high output battery.

should a dud battery cause this ?
any idea of the code meaning ?
should the alarm have gone off if the battery drained to 1v ?

Merry Christmas to you too.

Gary

[Clan]

maybe the siren has gone faulty and drained the battery , i would put the battery on a slow charger for a couple of days and see if it will recover ... the volvo battery has a 3 year guarantee if it IS faulty ...