Bay Technical Associates 525H, 5218H, 528H, 529H Peripheral-to-multiport-to-host communication

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Peripheral-to-multiport-to-host communication:

When a peripheral device transmits data to the host device through a peripheral port, the data is received and stored in a 3740-character receive buffer (or 7740 receive buffer for 525 units with Option 20) which in turn retransmits it to the host device through the host port. After the buffer receives 3720 characters (or 7720 characters for 525 units with Option 20), the multiport will make the peripheral port CTS (Clear-To-Send) line false (negative voltage), signaling the peripheral device that it cannot accept more data (however, in reality it can accept another 20 characters before overflowing the buffer).

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

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

When the multiport is sending data to the host device through the host port and the host device cannot receive any more data, the multiport will expect to see a false condition on the DTR line or receive an XOFF character.

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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 USER-PROGRAMMABLE Configurations Factory POWER-UP Default 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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