Legacy X3-Pro Protocol; Advanced Product Functions; Uart Interface Self-Detection; Autobaud: Self-Detection Of The Serial Link Data Rate - Adeunis RF ARF868 Guia Del Usuario

ARF868 Radio Modems - User guide version V1.6
Transparent mode with sub-network:
The sub-networks enable groups of products to be created that communicate with each other within the same sub-network. Products in sub-
network 1 cannot see those in sub-network 2 and vice versa. On the other hand all the products are visible between themselves within the
same sub-network.
• S220=0 (transparent mode)
• S253=Number of the sub-network varying from 1 to 255
when register S253 is set to 255, the frame is broadcast to the whole of the sub-network.
Addressed mode without sub-network:
In the addressed mode without sub-network a product communicates with a specified addressee. Only the addressee receives the frames from
the transmitting products. The configuration required for this mode of communication is as follows:
• S220=1 (address mode)
• S253=0 (no sub-network)
• S252=local address (16 bit address)
• S256=address of the recipient (16 bit address)
When register S256 is set to 65535, the frame is broadcast and visible by all equipment within range.
Addressed mode with sub-network:
The products always communicate within the same sub network. This means that two products with identical addresses and different sub-
network numbers do not communicate with each other. The only case of inter-network communication is when S256=255 and S253=255.
• S220=1 (address mode)
• S253= sub network number varying from 1 to 255 (255 is used for broadcast between the sub-network)
• S252= local address (address on 8 bits)
• S256= recipients address (address on 8 bits, 255 is the broadcast address within the sub-network)

3.2. Legacy X3-PRO protocol

The "legacy X3-PRO" protocol provides the ARF868 modem with total "air" compatibility with the previous generation Adeunis-RF X3-PRO
type modems.
Compatibility is provided for Narrowband and Wideband modes, and for Address and Transparent modes.
Please refer to the dedicated application note: ARF868 Radio Modems: «Legacy X3-PRO» mode, available on our website.

4. Advanced product functions

4.1. UART interface self-detection

The ARF868 modem has automatic interface detection at switching on enabling a selection of the RS232 or RS485 mode. Automatic detection
is activated when interface selection register S215 is positioned on the value 4.
For detection in the RS485 mode it is essential to have an earth connected to the product. Otherwise the detection motive "U" cannot be taken
into account.

4.2. Autobaud: Self-detection of the serial link data rate

On switching on with the SubD9 cable connected, the modem detects the data rate on the serial link of the monitoring equipment in order to
synchronise itself on its parameters.
For this detection to be performed, the equipment must send, before any command or character chain, the synchronisation command: " U "
After a positive reply from the modem, it is then operational and switches to the communication mode. It will be capable of transferring the
characters seen on the serial link onto the Air link or entering the command mode (see § 5.2 command mode input/output).
Command Description
U (upper case) Allows automatic detection of UART data
rate (see note 1).
Note :
To this request the modem will reply by the configuration that it has detected: type of link, UART data rate. E.g.: RS232, 9600.
If the modem does not reply or replies by another character chain to the synchronisation request U, a new test can be attempted, after having
disconnected and reconnected the electricity supply to the appliance. If these attempts produced no effect, check that the serial link of the moni-
Answer
Returns the parameters of the serial link :
RS232 or RS485 and data rate.
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