Category : Communication (modem) tools and utilities
Archive   : COMHELP.ZIP
Filename : COMHELP.003
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¬è °?The Modem Status Register provides the current state of certainè¸ P¸ è 跫蹯3modem (i.e. RS-232) signals to your PC's processor.èG¿JèY«¿èyè6¹ è߸ P趹
èÒ衵¸ P¸ èèI«èK¯:In addition, four of the eight bits (bits 0-3) are set to èÒ¸ P¸ èPèûªèý®4logical 1 whenever its 'mate' signal changes state. è¿J調輬èy¹ è"¸ PèÞµ¹
èèä´¸ P¸ èáèªè®7Whenever a 'Delta' signal is read, (bits 0-3 inclusive)è¸ P¸ èèAªèC®$it is reset to logical 0 by the UARTèà¿Jèò©¿è¬èϹ èx¸ Pè4µ¹
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èWè&´¸ P¸ è#èΩèÐECARRIER DETECT is provided to the UART by a modem. It indicates that èL¸ P¸ èÊèu©èw:analogue carrier is being received on the telephone line. èþ¿Jè©¿è0«èí¹ è¸ PèR´¹
èèX³¸ P¸ èUè ©è@Generally this means that the modem you have called, or the one è¸ P¸ è謨讬,that called you, is ready to send you data. èC¿JèU¨¿èuªè2¹ èÛ¸ Pè³¹
èÎ貸 P¸ èèE¨èG¬H...many PC modems can force this RS-232 signal (pin 8) to be constantly èÀ¸ P¸ è>èé§èë«*high via a strapping or register option...è¿J觿贩èq¹ è¸ PèÖ²¹
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èܱ¸ P¸ èÙè§è«E...this signal is also known as 'RLSD' (Receive Line Signal Detect). è¸ P¸ èè+§è-«<...Modem Manufacturers often mark it as 'CO' (Carrier On)...貿JèĦ¿èä¨è¡¹ èJ¸ Pè²¹
è=è ±¸ P¸ è 账趪C...If the signal is missing, you can be sure that your modem is NOTè4¸ P¸ è²è]¦è_ªC"hearing" the far-end modem. Many communication packages require itèݸ P¸ è[è¦èª;before they'll work. It has no effect on the 8250 Receiver.è¿Jè ¥¿èÀ§è}¹ è&¸ Pèâ°¹
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èèÔ¯¸ P¸ èÑè|¥è~©4RING INDICATE goes to logical 1 when the associated è¸ P¸ èè4¥è6©