การสื่อสารข้อมูลแบบอนุกรมมาตรฐาน RS-232C |
คุณสมบัติของสัญญาณไฟฟ้า
ตารางที่ 1
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2. ตัวขับสัญญาณจะต้องส่งสัญญาณระหว่าง -3 ถึง -25V และ 3 ถึง 25 V และยอมให้มีการลดทอนของสัญญาณ ได้ไม่เกิน 2V
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Protective ground |
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Transmitted data |
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Received data |
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Request to send |
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Clear to send |
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Data set ready |
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Signal ground (common return) |
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Received line signal detector (data carrierdetect) |
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(reserved for data set testing) |
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(reserved for data set testing) |
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(Unassigned) |
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Sec. Rec'd. line sig. Detector |
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Sec. Clear to send |
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Secondary transmitted data |
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Transmission signal element timing (DCE source) |
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Secondary received data |
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Receiver signal element timing (DOE source) |
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(Unassigned) |
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Secondary request to send |
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Data terminal ready |
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Signal quality detector |
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Ring indicator |
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Data signal rate selector (DTE/DCE source) |
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Transmission signal element timing (DTE source) |
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(Unassigned) |
ตารางที่ 3 แสดงชื่อของขาสัญญาณเรียงตามลำดับหน้าที่ของสัญญาณ
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- | - |
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Protective ground |
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Signal ground/common return |
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Transmitted data |
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Received data |
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Request to send |
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Clear to send |
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Data set ready |
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Data terminal ready |
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Ring detector |
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Received line signal detector or data carrier detect (DCD) |
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Signal quality detector |
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Data signal rate selector (DTE) |
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Data signal rate selector (DCE) |
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Transmitter signal element timing (DTE) |
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Transmitter signal element timing (DCE) |
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Received line signal element timing (DCE) |
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Secondary transmitted data |
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Secondary received data |
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Secondary request to send |
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Secondary clear to send |
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Secondary rec'd line signal detector |
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หน้าที่ของขาสัญญาณกลุ่ม Interchange Circuit จะเป็นดังนี้
วงจร AA : Protective Ground
วงจร AB : Signal Ground หรือ Common Return
วงจร BA : Transmitted Data
วงจร BB: Received Data
วงจร CA : Request to Send
วงจร CB : Clear to Send
วงจร CC : Data Set Ready
วงจร DC : Data Terminal Ready
วงจร CE : Ring Indicator
วงจร CF : Received Line Signal Detector
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Signal Quality Detector |
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Data Signal Rate Selector (DTE Source) |
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Data Signal Rate Selector (DCE Source) |
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Transmit Signal Timing (DTE Source) |
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Transmit Signal Timing (DCE Source) |
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Receive Signal Timing (DCE Source) |
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Secondary Transmitted Data |
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Secondary Received Data |
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Secondary Request to Send |
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Secondary Clear to Send |
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Secondary Received Signal Detector |
การกำหนดจุดข้อต่อของ RS232C
การต่อสาย RS232C แบบที่ไม่ใช่มาตรฐาน
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