FOCUS Enhancements TView Quad Scan Manual - Manual (Page 31)

TView QuadScan User's Manual 0092-5000-200
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4.3.3 Selecting the QuadScan’s address
In an RS-422, there may be as many as 8 QuadScans operating within a system. In order to provide a control mechanism
to differentiate each QuadScan, the user must program each QuadScan’s address using the Front Panel.
Programming the address is a simple procedure. Turn the QuadScan on, or cycle the control sequence such that the
Power Up Identification is visible (i. e. “QUADSCAN”) on the LED display. Press the Right Arrow Button. You will see
the QuadScan’s address indicated on the LED display. When you are finished, press either the + button or the - button.
The QuadScan will remember its address until you change it in the same fashion.
The address circuitry is active even when you are using the RS-232 link (which does not permit multiple QuadScans or
other devices to be connected in a multiple unit configuration). The default address is 0.
4.3.4 Sending Communications Commands to the QuadScan
The serial port of the QuadScan accepts serial data at 9600 baud, 8data bits, no parity bit, 1 stop bit. It is essential that the
serial communications device that delivers commands to the QuadScan be set up in this fashion.
The QuadScan accepts 8 bit characters as commands. The commands to turn the QuadScan on and off are received as
strings of ASCII alphabetic characters and binary numbers. For the purposes of this manual, all ASCII characters and
binary numbers will be referred to with the decimal numbering sequence (i. e. the minimum value of a byte is 0, the
maximum value of a byte is 255, the value of an upper case A is 65).
The Command sequence for communicating with the QuadScan is as follows:
1) The Activation Command is given. The Activation Command consists of the character string: QSRONx
(where x is the address of the QuadScan). The Activation Command (and all other commands) must be followed by a
Carriage Return (ASCII character value of 13 decimal) to be accepted.
The following byte string (using decimal values for ASCII characters) indicates a valid Activation Command for a
QuadScan previously programmed to be address 3:
81 83 82 79 78 03 13
Q S R O N 3
If the QuadScan receives any unexpected input before the reception of the Activation Command, it will ignore it. If it
receives an unexpected byte during the transmission of the Activation Command, the Activation Command must be re-
transmitted (the Activation sequence is reset).
2) Individual Commands are given. Any number of commands may be given after the QuadScan is activated. The
QuadScan individual commands consist of 2 byte strings. Each 2 byte string is an internal Register Number Byte
followed by a Value Byte. The Value Byte has a different meaning and legal range for each register. Each command ( i.
e. Register Number Byte, followed by Value Byte) must be concluded with a Carriage Return.
The Value Byte provides “absolute information” if the parameter in question is a Toggle or Multiple Choice Item. If the
parameter in question is a range item, the Value Byte provides “relative information” incrementing or decrementing the
existing value of that parameter by on count.