The Honeywell 470-12 is a 12 volt DC powered water detection module. There is a single 470PB water probe included with the module, however it does support up to two probes. There is no wiring included. Honeywell also makes the FP280 water probe. Basically the same probe design with 16.5 feet of cabling and a resistor already connected. If you are looking for a second probe, this is your best bet. You may even be able to splice off some of the wiring and make both runs with the included amount of cable. When using 22AWG wire the probe should be no more than 20 feet from the module. For longer runs, you can use 20AWG and go up to 100 feet, though it is recommended to stay within with 20 feet for ideal operation.
Generally, the 470-12 is wired to an alarm system's auxiliary power output; the same terminals used to power keypads. On a VISTA-20P, you would wire the 470-12's positive power to terminal 5 on the ECP bus 12 volt output. Then wire the ground to panel terminal 4.
The third pair of connections is the data wiring to the alarm. The module has a Form C contact output so it supports both normally open (NO) and normally closed (NC) configurations. Depending on how the zone is programmed, you need to wire the common (C) and either (NC) or (NO) depending on how you program the input type on the security system. If you want to supervise the wiring, you can wire an appropriate end of line (EOL) resistor at the 470-12. Wire in series for (NC) operation. Wire in parallel for (NO). Then program the zone's hardwire type to EOLR.
After programming the input type to the appropriate configuration (NC, NO or EOLR), you can set the zone to 24 hour auxiliary (Zone Type 8 - 24 hr aux). Anytime the probe's prongs are shorted, it will trip the corresponding zone and trigger a keypad alarm. If you have central station monitoring you can set it up to report to them as well. You can also setup a text and/or email alert from services like Total Connect 2.0 or Alarm.com.