Omega Speaker Systems VR200 instruction manual Start-stop Asynchronous Communication, Text

Page 9

If A < B, then signal = 1

If A > B, then signal = 0

1.4.1 Start-stop (Asynchronous) Communication

The built-in RS-422-A interface communicates based on the start-stop (asynchronous) system. The start-stop system first adds the start bit to the head and then in turn adds the data bits (7 or 8 bits), parity bit, and stop bit(s) to every transmission of each character (see Figure 1.4). Define the address of the RS-422-A interface built in the VR200 recorder, baud rate, data length, parity bit, and stop bit(s) in the SETUP mode on the VR200 recorder.

The start bit is automatically added and thus need not be set.

Idle status of the line

1

0

One character

Data bits

(7 or 8 bits)

Line released due to the idle status (broken line) or continued by the start bit of the next data (solid line).

Stop bit

1

Start bit

Parity bit: odd, even or none

1 or 2

Figure 1.4 Configuration of Each Character in Start-stop System

1.4.2 Text

Each communication data usually contains more than one character, to which a terminator character is appended. This is referred to as a text. See also Figure 1.5.

One character

Terminator

A

B

C

D

E CR LF

One text

Figure 1.5 Structure of Text

The built-in RS-422-A interface identifies each text by regarding the reception of a terminator as the end of the text. See also Figure 1.6.

 

 

 

 

 

 

Identifies text 1.

 

 

 

 

 

 

Identifies text 2.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A

 

B

 

C

CR

LF

 

D

E

F

 

G

CR

LF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Text 1

 

 

 

 

 

 

 

Text 2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1.6 Example of Two Texts Where Terminator Is CR/LF

1 - 4

Image 9
Contents User’sGuide Servicing North America Trademarks PrefaceContents Time Chart Initial Status Errors During RS-422-A Output Transmitting FunctionsProgram Examples Interface Specifications Installing the RS-422-A InterfaceCable Termination Interface Terminal Terminal AssignmentData Configuration Communication WiringText Start-stop Asynchronous CommunicationBuffer Overflow Input BufferSetup Procedure Setting up the RS-422-A Communication InterfaceIdentifier ParametersTerminator Setting the Range and Scale List of Program Set CommandsFormat SRp1,mode Example SR01,SKIPFormat SRp1, mode, p2 Example SR01, DI,Format SRp1, mode, p2, p3, p4, p5, p6, p7, p8 Setting Alarms Setting the Waveform Span Rate TIME/DIV Setting the UnitSetting the Clock Copying the Channel SettingsSetting the Discrete Zone Display Setting the Partial Expanded DisplaySetting the Tag Setting the Data File Name File Setting the Trip LevelSetting the Summer/ Winter Time DST Setting the LCD Brightness and LCD Saver LCDExample MD02, ON, on Format MDp1, p2, p3Alarm Acknowledge List of Program Control CommandsStandard Screen Call Initializing the Data MemorySaving the SET Configuration File Loading the SET Configuration FileSelecting the Output Data Selecting the Output Format for Measured DataMessage Writingfor the VR 200 with style number 2 or higher Execution of Trigger Status OutputRequests for the data to be prepared in the buffer Close Command Open CommandESC O Crlf ESC C CrlfSequence see also Sections 2.3.7 Introduction to Output Data FormatsOutput Data Formats Output Format of Measured Values in Ascii ModeOutput Format of Measured Values in Binary Mode Output Format of Parameter Settings Output Format of Unit and Decimal Point Information Time Chart Initial Status Output Preventing ErrorsESC S CR LF How to Request Error Message OutputTiming of Resetting the Error Status Environment Program ExamplesOpen TEST.DAT for Input AS #2 Others LF is sent automatically 210 ‘ 220 ‘ Open COM11200,N,8,1,LF AS #1 Print a Appendix 1 Ascii Code Table AppendixFile Name Length Appendix 2 File Naming RulesLowercase/Uppercase Letters System-reserved File NamesIndex Index for Command Reference Warrant Y/ Disclaimer Temperature