24 February, 2010
RBH Access Technologies Inc.
24 of
26
TB61_PC-
100 for AxiomV™
Note that all the various communications levels (RS232, RS485, and TTL)
are at all times carrying the same data, i.e. the exact same for the LEFT
(‘IN’) RJ45 RS485, will be on RS232 as well as TTL.
Initialization of the Network
At power up, the NODE ID's are automatically established from the readers'
physical connection position on the network. This whole process takes about 3.5
seconds at power up and consists of the following sequences.
1. Each reader powers up and sets its data flow in a right hand direction.
2. Each reader then continuously sends ' * ' s out of their right hand RS485
ports, and pre-pares to receive this character in their left hand RS485 ports.
This character is sent out in single bursts every 25ms. This avoids any
framing errors should a reader not be able to lock onto the data stream in the
correct position from start up.
3. If an ' * ' is received in the left RS485 port, the TAG LED (slave indicator) is
illuminated to indicate this. Each reader, except for the first reader on the
reader network, will therefore receive this character on its left hand RS485
port.
4. The first reader has now been established.
5. This process of sending out the right hand RS485 port lasts for 1 second.
When the PC100 powers up it takes into consideration the initialization sequence
and waits for about 4 seconds before beginning to communicate with the first
reader.
Wavetrend Health Monitor
Approxim
ately once per minute the PC100 will “ping” all readers to see if they are
still communicating. If a reader fails to respond a Tamper message will be sent
to the Axiom system for the reader. Once a previously identified non-responsive
reader reports correctly a “Tamper Restore” message will be sent.
