AXIOMUNC500 Silkscreen Legend

The UNC500 has been designed to take over the functionality of the Axiom NC100 (network controller), 

an RC-2 (reader controller) and an LIF (local area network interface). The network interface can also 

contain a POE (power over Ethernet) converter.

Communication

The UNC500 has three RS485 ports and an Ethernet 10/100 interface. Depending on the hardware 

configuration all three channels may not be available. Communications from the host computer running 

Axiom software can be achieved in the following ways; either via Ethernet through a socket interface or 

via RS485 through a direct connection to a designated channel. The Ethernet interface may be single or 

dual ported 10/100 Mbs, depending on how the board is configured. The UNC500‟s RS485 channels 1, 

2, or 3 may be programmed as „HOST‟, „DNET‟, „NCNET‟, or „CNET‟. Use the DIP switch to select 

baud rate for Host communications as 9600, 38400, 57600, or 115200.

Networks 

There are three networks supported by the UNC500 these are:

1) Host Communications through the Ethernet or direct connection.

2) Device Communications for devices such as additional RC-2s starting at address 2, Alarm Keypads, 

IOC-16 controllers, and PC100.

3) Controller Communications for controllers such as additional UNC500s or for NC100s via:

a. NCNET a protocol designed for RS485 communications between UNC500‟s only.

b. CNET for connection with NC100‟s.

Outputs

There are four form C relays and four open collector outputs that can be programmed as general purpose 

or default applications. Although the contacts are rated at 12 amperes at 125vac the surge protectors 

prevent voltages greater then 40vac or 56vdc from being applied. The recommended use of the relays is 

to provide isolated outputs for driving electric strikes or magnetic locks at a maximum voltage of 24v.

The open collector outputs are current limited to 100 milli-amperes direct current only.

Auxiliary Power

A thermal fuse protected power output rated at 500 milli-amps 12Vdc.

Inputs

There are eight inputs used for sensor connections. Four are configured as general purpose and four are 

either programmed for default application or for general purpose. The software provides configuration 

information used to decode the state of the contacts. The following table illustrates the seven circuit type 

assignments. Note that when an input is armed it will only report alarm or restore states. All “normal” 

states are translated to “restore” and all other states are translated to “alarm”.

Reader Interface

Two standard wiegand interfaces provide the following connections for typical proximity readers:

1) Thermal fuse protected power (500ma @12vdc).

2) Wiegand data interface.

3) Reader tamper input (s). Initially if open it will be ignored but once a short is connected it will 

report a reader tamper alarm whenever the input is opened.

4) LED and beeper outputs are open collector current limited to 100ma.

Battery Charger

The battery charger routes input power from the 12v input source or 15V POE module through a series 

power resistor (24 Ω) and constantly monitors the battery voltage. If the battery voltage exceeds 13.8v

the battery charger turns off until the voltage has reached 12v. If the battery terminals are not connected 

this could lead to a constant pulsing of the battery charger output and reporting the battery state as battery

– low, battery – normal. To prevent this from happening the battery test cycle is initiated when ten 

cycles are counted. If the battery test fails the charger is turned off until a power failure is detected or a 

battery is re-applied.

Reverse Battery Protection

A combination of a three ampere diode and a 1.6 amp thermal fuse protects against accidental connection 

of a battery in the reverse direction.

Battery Test

A battery test cycle is operator initiated or scheduled. When initiated the charger is turned off and a 

24Ω resistor provides a load to the battery for about ten seconds. If during this period the voltage drops 

below 10 volts a battery alarm message is sent to the host, otherwise a battery normal message is sent.

Fuse Monitoring

Besides monitoring the battery voltage the UNC500 also monitors the input voltage (DC), auxiliary 

voltage (aux) and the reader voltage (reader) and reports to the host whenever the state changes.

Diagnostic LED’s

Each RS485 circuit has a red and green LED to indicate when a signal is received or transmitted.

Diagnostic 1 is a bicolour LED when red indicates receiving data from the host and when green indicates 

transmission of data.

Diagnostic 2 will flash slowly when connected to the host and quickly when not connected.

Diagnostic 3 will flash when a power problem such as a low battery or low auxiliary power is detected.

Tamper Detection

A tamper wire may be connected to JP1 located close to the power resistors on the board. A short to this 

input is normal and an open is alarm.

RAM Memory

The static ram memories hold the database from the host that is downloaded using Axiom software. The 

coin cell provides power to these memories as well as the real time clock.