Vivid VTS-4600, Operation Manual

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External Control
In addition to using the display keypad or remote control unit, you can control the display using a serial (RS-
232) link to send ASCII commands and receive responses to those commands.
You also use discrete infrared (IR) control c odes to program a third-party remote control unit. For more
information, refer to
Using Discrete IR Codes on page 46.
6.1 Serial Communications
The display uses a simple text-based control proto col to take requests from control devices and to
provide responses to such devices. This section describes how to send control messages over a serial link
between the display and an automation/control system or a PC running a terminal emulation program such
as Windows
®
HyperTerminal or Tera Term.
RS-232 Connection and Port Configuration
Connect your control system or PC to the RS-232 input of the display as shown in Figure 3-2.
Configure the RS-232 controller or PC serial port as follows: no parity, 8 da ta bits, 1 stop bit and no flow
control. Set the baud rate to 115200, to m atch that of the display RS-232 port.
Command and Response Format
Commands sent from an automation/control system or PC to the display must have the following format:
[STX] [IDT] [TYPE] [CMD] ([VALUE] or [REPLY]) [ETX] [CR]
Where:
• [STX] indicates the start of the command data (always 07).
• [IDT] is the display ID (always 01).
• [TYPE] is the command type:
• 00 = return to host (response from the LCD panel)
• 01 = read / action
• 02 = write
• [VALUE] is the parameter setting for the command.
• [REPLY] is the parameter setting for the command, acknowledged by the display in its response to a
command.
• [ETX] indicates the end of the command data (always 08).
• [CR] is the ASCII carriage return key (0x0D).