Owner`s manual
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NOTE: The following discussion for hardware handshaking assumes
you have DTE serial ports installed on the Model 24H.
Host-to-Model 24H-to peripheral communication:
When the host device transmits data to the Model 24H host port, the
data is received and stored in a 426 character buffer which in turn
retransmits it to a selected peripheral device through a peripheral port.
During transmission, when there are only 19 bytes available in the
buffer, the Model 24H will make the host port's DTR (Data Terminal
Ready) line false (negative voltage), signaling the host device that it
cannot accept more data. When the buffer of the Model 24H can
receive more data, the unit will make the host port's DTR line true
(positive voltage).
When the Model 24H retransmits the data to the peripheral device and
the peripheral device cannot receive any more data, the Model 24H will
expect to detect a false condition on the peripheral port's CTS
(Clear-to-Send) line. When the peripheral device can receive more
data, the Model 24H will expect to see a true condition on the CTS line.
Peripheral-to-multiport-to-host communication:
When a peripheral device transmits data to the a Model 24H peripheral
port, the data is received and stored in a buffer (512K standard,
available up to 4.5 MB) which in turn retransmits the data to the host
device through the host port. During transmission when there are only
15 bytes left in the buffer, the Model 24H will make the peripheral port's
DTR line false signalling the peripheral device that it can no longer
accept data. When the buffer empties to the point where it can accept
more data, the Model 24H will make the peripheral port's DTR line true.