Purpose
Although electric and hydraulic entry doors have greatly improved access to public buildings, some are slow and difficult to operate, especially for individuals confined to wheelchairs. The purpose of this document is to define a radio link and data protocol standard for use in equipment used to open the handicapped entry doors of public buildings. Following the guidelines of this document will allow original equipment manufacturers (OEM's) to design transmitters for the disabled and receivers for public access doors. A One-Link receiver will recognize any transmission designed according to this specification and will start opening the door as the individual approaches, minimizing any wait and physical challenge in opening the door.
Frequency
The frequency of transmission shall be 433.92 MHz ± 25 kHz
Radiated Output Power (transmitter)
The radiated output power shall be measured on an open field test site (OFTS) per FCC part 15 requirements. The peak output power shall be within 8dB of the FCC limit, using a 16.8dB duty factor.
Bandwidth (receiver)
The bandwidth (3dB) of the receiver shall be £ 200kHz.
Sensitivity (receiver)
The sensitivity of the receiver shall be defined as the lowest power delivered to a dipole which successfully activates the receiver under the following conditions:
· 50 ohm RF source
· tuned dipole, vertically oriented
· 3 meter open field test site registered with the FCC
· receiver and dipole shall be mounted 1 meter above the ground
The minimum sensitivity shall be < TBD dBm
Modulation
The modulation shall be on-off-keyed (AM) modulation.
Microchip KEELOQ Rolling Code Data Format (transmitter)
The data format shall use the Microchip KEELOQ rolling code algorithm. The KEELOQ system has become very popular in the garage door opener markets due to its security and a wide variety of available integrated circuits.
For reference literature and application notes see for reference Microchip's web site: www.microchip.com.
The selectable parameters of the KEELOQ encoders shall be defined as follows:
· Serial Number: the serial number used shall be 28 bits
· Decoder Option: SIMPLE
· Counter Overflow: NONE
· Low Voltage Trip: HIGH
· Baud Rate Select: 100uS ¼
Function Codes
The Keeloq data format includes the use of four function code bits. These bits facilitate the use of up to fifteen unique functions within the One-Link standard. The function codes shall be defined as follows:
|
S3 |
S2 |
S1 |
S0 |
Function |
|
0 |
0 |
0 |
1 |
Normal Door Operation: Enter Building |
|
0 |
0 |
1 |
0 |
Normal Door Operation: Exit Building |
|
0 |
0 |
1 |
1 |
Reserved for future use |
|
0 |
1 |
0 |
0 |
Distress – request for HELP |
|
0 |
1 |
0 |
1 |
Elevator UP |
|
0 |
1 |
1 |
0 |
Elevator DOWN |
|
0 |
1 |
1 |
1 |
Reserved for future use |
|
1 |
0 |
0 |
0 |
Reserved for future use |
|
1 |
0 |
0 |
1 |
Security ON |
|
1 |
0 |
1 |
0 |
Security OFF |
|
1 |
0 |
1 |
1 |
Reserved for future use |
|
1 |
1 |
0 |
0 |
Reserved for future use |
|
1 |
1 |
0 |
1 |
Temperature UP |
|
1 |
1 |
1 |
0 |
Temperature DOWN |
|
1 |
1 |
1 |
1 |
Reserved by Microchip |
The One-Link receiver shall provide two normally open relay contacts. After reception of a One-Link transmission the relay coil shall be energized and the contacts closed for 500mS±100mS. After a relay has been energized the receiver shall not allow any additional activations for >2 seconds. The relay contacts shall meet the following:
· Peak current capability > 1Amp
· On resistance < .5 ΩO
· Off resistance > 10 MΩO
Software (receiver)
The One-Link receiver shall include a non-volatile memory (NVM) of at least 1024 bytes. The memory shall be used to store the 16 least significant bits of serial number, and 16 bits of synchronization counter for each transmitter it detects that has transmitted a valid KEELOQ data stream encrypted with the oneLINK manufacturer's key. The assembly code can be downloaded from oneLINK's website.
Software Flow Chart
Requirements for One-Link certification
Any manufacturer intending to display the One-Link compatible logo shall complete the following requirements:
- Submission of samples
- Submission of a test report documenting field strength and sensitivity testing from a FCC registered open field test site.
Microchip technology will offer for sale a oneLINK evaluation kit. This kit will provide several encoders and decoders with the oneLINK key preprogrammed into the chips. OEM's desiring to build oneLINK compatible systems can then build functional prototypes for evaluation and submission to oneLINK