Other devicesItem Maximum number of devicesFControl box 1GSwitching hub*10 —HComputer (forprogramming) —INetwork camera 500*11JAccess controller 1 per lobby stationKElectric lock 1 per lobby station1 per door stationLOpen door sensor 1 per lobby stationMPower supply unit1 per lobby station1 per room monitor*21 per door station*2NR1 R2 R31 2Relay box 1 per door station*12*1 Up to a combined total of 45 lobby station and door station cameras can be registered to a room monitor for easy cameramonitoring.For information about software updates for each device, consult your dealer.*2 If room monitors and door stations are not powered by Power over Ethernet (PoE), a power supply unit is required.*3 Up to 256 rooms can have multiple room monitors. All other rooms can have only one room monitor. For more information, referto the documentation of the control box (PC Programming Manual).*4 Up to 18 SIP phones can be registered to a room monitor for easy calling.Up to 90 SIP phones can be registered to a lobby station for easy calling.For information about software updates for each device, consult your dealer.*5 By installing the [Video Intercom System] app on a smartphone, you can expand the features available when using theVL-VN1800 control box system with a smartphone. In order to use the [Video Intercom System] app, you must download it toyour smartphone and register your smartphones with your "main" room monitor. For information about downloading and installingthe [Video Intercom System] app, visit the following website for more information.https://panasonic.net/cns/pcc/support/intercom/vn1900Compatible mobile devices: iPhone 5s and later, iPad Air and later (iOS 10 and later), Android devices (Android 4.4 and later),as of June/2019.*6 Residents that have a room monitor: A maximum of 6 devices (including "main" room monitor, "sub" room monitors, andsmartphones) can be registered to each residence.*7 Depending on the number of room monitors installed in a residence, the number of smartphones that can be registered is limitedas shown in the following."Main" room monitor "Sub" room monitor Smartphone1 — 41 1 41 2 31 3 21.1.5 Before Operating the Telephones16 Operating Manual