Redlake MASD MegaPlus 4.2i, Руководство пользователя

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Mega Plus
®
Model 4.2i
3. CAMERA OPERATION
3.1 Introduction
The
Mega Plus Camera, Model 4.2i does not have any manual controls. Camera operation is
accomplished by commands sent to the camera through a serial data link from a personal
computer. In this chapter we will present the various operating modes of the camera with an
explanation of the function followed by the command sequence that must be transmitted by the
computer. The control lines to the camera can be configured as an RS232 or an RS422 serial
data link. The camera is ordered from the factory configured one way or the other. The
command syntax is the same in either case.
3.2 Serial Communications Protocol
The camera uses a full duplex UART type asynchronous system, using standard nonreturn-to-
zero (NRZ) format (one start bit, eight data bits, one stop bit, no parity). The baud rate is fixed at
9600. The character code is based on the ASCII standard.
The character flow control protocol is XON/XOFF. XON is assigned DC1 (control-Q) and XOFF
is assigned DC3 (control-S). The receiver sends the XOFF character when it wants the sender to
pause in sending data and an XON character when it wants the sender to resume.
The camera will recognize a command as three command characters, followed by a space bar
character, followed by an argument that consists of one or more characters, ended by the
carriage return and line feed characters. The camera responds to a valid command with a
carriage return and line feed (CR-LF).
The camera will recognize a query as three command characters, followed by the question mark
character, then ended by the carriage return character.
The camera responds to a query with three command characters, followed by a space bar character, followed by an
argument that consists of one or more characters, then ended by carriage return character and line feed (CR-LF).
3.3 Error Messages
The camera can respond to an erroneous command or query in one of three possible ways.
MESSAGE FROM CAMERA EXPLANATION
ERROR-SYNTAX
The camera cannot make sense of the command.
ERROR-ARGUMENT OUT OF RANGE The command is recognized, but the argument is
out of range or indecipherable.
ERROR-TRANSMISSION The receiver detected a transmission error such
as buffer overflow, parity, noise, or framing
3.4 Mode Control
The Mega Plus Camera operates in one of three modes, TRIGGER, CONTINUOUS, or
CONTROL. The mode of operation is selected by the mode command. The mode command’s
fourth option, PARALLEL INTERFACE, delegates mode selection to three control lines, MC0 -
MC2, input through the Digital Interface Connector
91000058-003 Revision A 3-1 USER’S MANUAL