Can I add a Lyric LKP500 to an L5200, L5210, or L7000?

The short answer is, no, you can’t.

The LKP500 is a SIX Series wireless keypad made for use with the Lyric Controller and any other Honeywell panel that supports the use of SIX Series devices. SIX Series devices are encrypted, bi-directional devices that are in constant communication with the control panel, providing feedback on their ability to check in, Tamper, and their power/battery status. The LKP500, for example, checks in with its panel at least once every 60 seconds. If the panel doesn’t hear from a particular LKP500 keypad for more than 200 seconds, it puts the supervision zone for said keypad into a trouble state. This keypad has a range of approximately 300 feet from the main control panel. The LKP500 will signal a Tamper if removed from its back plate, and there is a breakaway on the back. You can mount a screw through it into a wall stud, so if someone tries to pull the keypad off the wall, the breakaway will stay in place with the screw, tripping the back plate tamper.

The L5200, L5210, and L7000 support the 5828 and 5828V wireless keypads. They use a House ID protocol to communicate with these keypads and the keypads are unsupervised. The information that passes back and forth between panel and keypad is not encrypted, and is therefore less secure, and their range is limited to about 50 feet from the panel.