Bay Technical Associates 5218H, 528H, 529H, 525H Host-to-multiport-to-peripheral communication

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Host-to-multiport-to-peripheral communication

When the host device transmits data to a peripheral device through the multiport's host port, the data is received and stored in a 256- character transmit buffer which in turn retransmits it to a peripheral device through a peripheral port. During transmission, after the buffer receives 236 characters, the multiport will make the host port's CTS (Clear-To-Send) line false (negative voltage), signaling the host device that it cannot accept more data (however, in reality it can accept another 20 characters before overflowing the buffer).

If XON/XOFF handshaking is enabled and the host device does not respond, 8 characters later the multiport will send an XOFF character, signaling the computer that it cannot accept more data (however, in reality it can accept another 12 characters before overflowing the buffer).

When the multiport's buffer empties, the multiport will make the CTS line true (positive voltage) and send an XON character (if XON/XOFF is enabled), signaling the host device that it can accept more data.

When the multiport retransmits the data to the peripheral device through a peripheral port, and the peripheral device cannot receive any more data, the multiport will expect to see a false condition on the DTR (Data Terminal Ready) line or receive an XOFF character (if XON/XOFF is enabled). When the peripheral device can receive more data, the multiport will expect to see a true condition on the DTR line or receive an XON character (if XON/XOFF is enabled).

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Contents Series Multiport Controllers Page Copyright 1993 by Bay Technical Associates, Inc Table of Contents Federal Communications Commission Radio Frequency Page Page Below shows six applications, one for each mode of operation Factory POWER-UP Default Configurations USER-PROGRAMMABLE ConfigurationsUL and CSA Listed Page Page Page DCE Port Signals 500H Series DCE to DTE Device Page Factory default is Carriage Return 0D Hex Page Page Page Page Page Page Page Page Host-to-multiport-to-peripheral communication Peripheral-to-multiport-to-host communication Host-to-multiport-to-peripheral communication Peripheral-to-multiport-to-host communication Page Operation Protocol Enter Port Number 0=Exit,Return For 110 135 300 600 1200 2400 4800 9600 Enter request 0AH Section Control Mode of Operation Main Menu SET Message Terminate Character TITC22*233343526Y130A4250*51466X Page Page Page Solutions Problem Garbage Data Symptom Missing Characters Symptom Random Garbage Characters Problem Cant Select Peripheral Port from Host Device Problem Cant Receive Data from Peripheral Ports Ccitt DOS Page Page Page Uart Other Baytech Products Page Page Series Multiport Controllers Page
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