How do I connect a wired iBus keypad to the VISTAH3?

To connect a wired keypad to the First Alert VISTAH3 iBus, connect the keypad's positive (+) wire to Terminal 18 (AUX) and the negative (-) wire to Terminal 17 (GND). Connect keypad A to panel Data A, and Keypad B to panel Data B. Once the keypad is connected, enroll using device discovery.

The First Alert VISTAH3 uses a 4-wire bus called iBus for communication with keypads and expansion modules. This replaces the older ECP bus found on legacy VISTA systems such as the VISTA-20P and VISTA-128BPT. The iBus carries both power and data across four wires that connect each keypad or expansion module to the main control board.

The iBus uses RS-485 architecture, a widely adopted industry standard for communication in programmable logic controllers (PLCs) and other industrial applications. By using RS-485, the VISTAH3 can support longer wire runsFollow these steps to connect and enroll a keypad to your VISTAH3 system:

1. Plan keypad placement. Choose an indoor mounting location near a main entry point or common area for easy keypad access. Try to avoid direct sunlight, moisture, and heat sources. Make sure the keypad wire can reach the control panel without any wire strain which can cause damage over time.
2. Run 4-conductor wire. Run wire from the panel to the keypad. Twisted, stranded cable is recommended. All keypads and other compatible iBus devices share the same four-conductor wiring loop, which carries both power and data. Multiple devices can be daisy-chained, home-run, or some combination of the two, depending on your installation layout. Follow the wire length and gauge limits outlined in the chart below:



Wire Gauge (AWG)	50mA or less	100mA	300mA	500mA	600mA
	#22	700' (213m)	350' (107m)	120' (37m)	70' (21m)	60' (19m)
#20	1,200' (366m)	600' (183m)	200' (61m)	120' (37m)	100' (30m)
#18	1,900' (579m)	950' (290m)	320' (98m)	190' (58m)	160' (49m)
#16	3,000' (914m)	1,500' (457m)	500' (152m)	300' (91m)	260' (76m)
The total current drawn on any wire run must not exceed the limits shown above, based on wire gauge

Source: VISTAH3 Installation & Setup Guide, “iBus Technology > Wiring" Page 15.




The length of all iBus wire runs for all partitions combined must not exceed 3000 feet (914m) when unshielded 4-conductor cable is used or 1500 feet (457m) if shielded cable is used. Shielded cable is typically not required.

3. Locate the iBus terminals. On the VISTAH3 main terminal strip, the iBus connections are labeled and arranged as follows:
   GND - Terminal 17
   AUX (+12VDC) - Terminal 18
   B (Data In, Yellow) - Terminal 19
   A (Data Out, Green) - Terminal 20
   These four terminals provide both operating voltage and bidirectional communication for each keypad and connected expansion module.
4. Wire the keypad to the panel. If the panel is already powered up, power it down by unplugging the DC power adapter and disconnecting the red battery lead. Match each terminal on the panel to the same marking on the keypad’s iBus connector:
5. Panel (GND, Terminal 17) → Keypad C (GND)
   Panel (AUX, Terminal 18) → Keypad D (+12V)
   Panel (B, Terminal 19) → Keypad B (Data In Yellow)
   Panel (A, Terminal 20) → Keypad A (Data Out Green)
   Tighten all terminal screws securely. Confirm that each conductor is properly secured by gently tugging on the wire after the terminal is tightened. Ensure there is no excess exposed copper.



If the keypad is being powered by a secondary power supply, such as the Honeywell AD12612, a common negative is required. Connect a wire from the DC negative (-) terminal of the power supply to the GND (Terminal 17) of the VISTAH3 panel.





6. Restore power and check keypad display. Once all wiring is complete, plug in the panel’s power adaptor then reconnect the battery. The keypad should power up and may display “Not Enrolled” or “Searching for Panel.” This indicates that physical wiring is good and the keypad is ready for enrollment.




Once the VISTAH3 powers up, if it isn't registered with AlarmNet360 within fifteen minutes, all connected iBus devices are enrolled automatically.

7. Enroll the keypad through iBus discovery. On a PROWLTOUCH or VISTAHTCHCWLC tap Menu > Tools > Enter Installer Code (4112 Default) > Programming > Scan iBus Devices. Your alarm dealer can also begin device discovery for you using AlarmNet360. Once in iBus Enrollment mode, the panel will automatically search for and list all connected iBus devices. Highlight the new keypad and assign it a device number and name, then press "Save". If you want to give each keypad a unique descriptor, like "Front Door", make a note of the keypad serial number or MAC address and program the descriptor in the supervision zone for that keypad. Zone numbers 800 - 815 are reserved for iBus and PROSIX wireless keypad supervision. PROSIX keypad supervision is mandatory while iBus keypad supervision is optional.
8. Verify communication. Once enrolled, the keypad will display system status and respond to commands. Test arming and disarming to confirm operation.