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Wrap Test for Half Duplex Modem

IP.com Disclosure Number: IPCOM000035069D
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Satoh, J: AUTHOR

Abstract

Disclosed is a wrap test for a half duplex modem which cannot send and receive data simultaneously, wherein analog data representing the original bit pattern from the modem is converted to digital data, the converted digital data representing the analog data is temporarily stored in a memory, the digital data is converted to analog data, and the analog data is fed back to the modem and compared with the original bit pattern. Referring to the figure, a microprocessing unit (MPU) 1 controls the operations of the circuits. In a normal data transmission mode, a switch (SW) 2 is switched to position A.

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Wrap Test for Half Duplex Modem

Disclosed is a wrap test for a half duplex modem which cannot send and receive data simultaneously, wherein analog data representing the original bit pattern from the modem is converted to digital data, the converted digital data representing the analog data is temporarily stored in a memory, the digital data is converted to analog data, and the analog data is fed back to the modem and compared with the original bit pattern. Referring to the figure, a microprocessing unit (MPU) 1 controls the operations of the circuits. In a normal data transmission mode, a switch (SW) 2 is switched to position A. Digital data stored in a memory area 3A of a memory 3 is supplied to a telephone line 5, in the form of analog data, through a loop including data bus 4, a serial/ parallel converter (S/P) 6, a half duplex modem 7, a filter 8 and the switch 2. Received analog data on the telephone line 5 is stored in the memory area 3A through the loop in the reverse direction. The modem 7 converts digital data to analog data, and vice versa. In the wrap test mode, the switch 2 is switched to position B. It is assumed that no error condition exists in the loop. The original bit pattern, for example, one-byte data 10110110, stored in the memory area 3A, is supplied to the loop, and the analog data representing the pattern 10110110 are supplied to an analog/digital (A/D) converter 9. The converted digital data pattern 10110110 is stored in the memory area 3...