The ADT Safewatch 3000 is ADT's version of Honeywell's Vista-20P Control Panel (usually called just "The Panel", and not to be confused with the Keypad(s), which are probably model(s) 6150 and/or 6160. The Panel is slightly modified for ADT, but not in any way pertinant to your question.
When you arm your system in any mode (STAY, AWAY, or MAX), the default protocol of the system is to sound a series of Keypad beeps during the Exit Delay, to alert you that it's counting down. I believe the minimum exit delay is 45 seconds.
You may have noticed that the beeps speed up in the last 5-10 seconds of the countdown, to let you know it's about to expire.
When you open a door whose zone is programmed as Entry/Exit Delay, the keypads are normally set to beep during the Entry Delay (minimum 30 sec.) to remind you to disarm. (Code + 1; or keyfob)
If you have your system set to "CHIME", Keypads will usually (depending on panel programming) beep when a door or window is opened.
All these keypad beeps--Arm, Disarm, Entry/Exit Delays, and Chime--are grouped together in panel programming. You can't separate them.
You can select which keypads will beep and which won't. This allows you to have a quiet KP in the bedroom but be reminded at the door to Disarm.
On the quiet KP(s), you can disable all the beeps, but you can't select some beeps and not others: I.e., if you disable the Exit Delay beeps after you arm, then you won't have Entry Delay beeps to remind you to Disarm; and you won't be able to have that keypad Chime when a door is opened.
If you still want to silence your keypad(s), then you'll need to go into your Panel's programming. Do do that, you'll need to download the Vista-20P Installation Manual.
http://www.alarmhawaii.com/Alarm Vista 15,20.pdf
Don't be daunted by the size of the manual. You'll only need to visit a couple of excerpts on 2 pages. But you should have the technical manual for any electronic system you have.
To tell you how to go about silencing your keypads, I need to know some
things:
(1) How many keypads do you have? And..
(2) What are the KPs' addresses?
The Vista-20P Control Panel (usually called just "the Panel") has addressable KPs so it knows which KP it's talking with. Read a KP's address by pressing 1 & 3 keys simultaneously and holding until it beeps and displays a 2-digit number between 16 and 23. That's the KP's address.
Keypads have physical keys to press. Touchscreens have "virtual" keys displayed on a screen. Keypads and Touchscreens are different in programming. If you have a Touchscreen, this would be the time to mention it.