Comtech EF Data LGAN, Инструкция по установке и эксплуатации

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LGaN
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Serial Interface Operation 5–4 MN-LGAN
5.3.3 EIA-485 (Full Duplex)
Two differential pairs - one pair for controller to target, one pair for target to controller.
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Controller-to-target pair - has one line driver (controller), and all targets have line-receivers.
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Target-to-controller pair - has one line receiver (controller), and all targets have tri-state drivers.
5.3.4 EIA-232
This is a much simpler configuration in which the controller device is connected directly to the target via a two-wire-plus-ground connection.
Controller-to-target data is carried, via EIA-232 electrical levels on one conductor, and target-to-controller data is carried in the other direction on
the other conductor.
5.3.5 Basic Protocol
Whether in EIA-232 or EIA-485 mode, all data is transmitted as asynchronous serial characters, suitable for transmission and reception by a
UART. The asynchronous character format is fixed at 8N1 (8 data bits, No parity, and 1 stop bit). Baud rates 2400, 4800, 9600, 19200, and 38400
are supported.
All data is transmitted in framed packets. The host controller is assumed to be a PC or ASCII dumb terminal, which is in charge of the process of
monitor and control. The controller is the only device that is permitted to initiate, at will, the transmission of data. Targets are only permitted to
transmit when they have been specifically instructed to do so by the controller.
All bytes within a packet are printable ASCII characters, less than ASCII code 127. In this context, the Carriage Return and Line Feed characters
are considered printable.
All messages from controller to target require a response (with one exception). This will be either to return data that has been requested by the
controller, or to acknowledge reception of an instruction to change the configuration of the target. The exception to this is when the controller
broadcasts a message (such as Set Time/Date) using Address 0, when the target is set to EIA-485 mode.