AMX UDM-RX02N, Руководство по эксплуатации/справочник

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UDM-RX02N NetLinx Programming
56 UDM-0808-SIG, UDM-RX02N and UDM-ABB-8-SIG Operation /Reference Guide
Serial Control Considerations With UDM-0808 and UDM-RX02N
The UDM-0808 (and DVX) has a native NetLinx interface which exposes the serial ports integrated into the
RX02N as standard NetLinx serial ports. While this makes using these ports a lot simpler than using them with
other UDMs (UDM-1604c, for example), the same physical transport is used, and this has some restrictions
which might not be apparent from the programming model.
The UDM series transports video, audio and data over a single CAT5 cable. Each CAT5 cable has four pairs –
three of these are used to transport the video (one pair for each of the color components).
The fourth pair is used to carry audio, data and power Audio from the hub to the RX02N is carried as a
standard AES3 digital stream. If the hub is operating with analog audio it is digitized in the hub before being
transported – the signal on the CAT5 cable is always digital.
Serial data from the UDM-0808 hub to the RX02N is embedded in the digital audio stream. This embedded
data has a potential throughput of approximately 10kbps. If the serial ports are configured to handle data rates
above this (38400kbps for example) then the hub will buffer incoming data. The buffers in the hub are very
large and dynamic, so this buffering should not be a problem in normal practice.
Rx data from the RX02N to the hub has a much slower data rate. The data is transmitted by modulating the
power supply and so is much more limited in throughput. The average data rate from RX02N to the hub is
around 50bps.
The serial port on the RX02N can be configured to the usual selection of baud rates, but the RX02N must
buffer this data and return it back to the hub at around 50bps (approximately 5 characters per second). The
buffer in the RX02N is limited to 256 bytes, so care must be taken in how return data is handled in order to
avoid buffer overflow.
In controlling most RS232 devices, the host usually sends a command string and the device replies with some
data. Most devices have command strings and replies in the 8-64 character range. Because return feedback
data is very slow, care should be taken programmatically not to depend on real time responses when
programming feedback logic.
The RX02N is primarily designed to control display devices which deliver the media content from the RX02N
via the UDM Hub. Most display devices use simple non-verbose protocol with limited and simple feedback
functionality. As such, the RX02N is ideal for one-way serial control (or IR control) of most display devices.
UDM-RX02N Serial SEND COMMANDs (Cont.)
"'RXON'"
Start transmitting received
characters to the Master
(default).
Enables sending incoming
received characters to the
Master.
This command is automatically sent by the Master when a 'CREATE_BUFFER'
program instruction is executed.
Syntax:
SEND_COMMAND <DEV>,"'RXON'"
Example:
SEND_COMMAND dvRXRS232,"'RXON'"
Sets the Rx serial port to transmit received characters to the Master.
"'SET BAUD'"
Set the serial
communication parameters.
Syntax:
SEND_COMMAND <DEV>,"'SET BAUD
<baud>,<parity>,<data>,<stop>'"
Variables:
• baud = baud rates are: 115200, 57600, 38400, 19200, 9600, 4800, 2400,
1200.
• parity = N (none), O (odd), E (even)
• data = 8 data bits
• stop = 1 bit
Example:
SEND_COMMAND dvRXRS232,"'SET BAUD 19200,N,8,1 '"
Sets the Rx serial port's communication parameters to 19200 baud,
no parity, 8 data bits, 1 stop bit.
"'TXCLR'"
Stop and clear all
characters waiting in the
transmit out buffer and
stops transmission.
Syntax:
SEND_COMMAND <DEV>,"'TXCLR'"
Example:
SEND_COMMAND dxRXRS232,"'TXCLR'"
Clears and stops all characters waiting in the Rx serial port transmit buffer.