Owner`s manual

39
COMPUTER-TO-MODEL 24-TO-PERIPHERAL
PERIPHERAL-TO-MODEL 24-TO-COMPUTER
When a computer transmits data to a peripheral device through a
computer port on the Model 24, the data is received and stored in the
spooling buffer (standard 512K; optional up to 4.5M) which in turn
retransmits it to a peripheral device through a printer port. During
transmission, when there are only 15 bytes available in the buffer, the
Model 24 will send an XOFF, signaling the transmitting computer that it
cannot accept more data.
When the Model 24 retransmits the data to the peripheral device
through a printer port, and the peripheral device cannot receive any
more data, the Model 24 will expect to see a low on the CTS
(Clear-to-Send) line or receive an XOFF. When the peripheral device
can receive more data, the Model 24 will expect to see a high on the
CTS line or receive an XON.
When the buffer of the Model 24 can receive more data, the Model 24
will send an XON to the transmitting computer.
In the reverse direction (Peripheral-to-Model 24-to Computer),
handshaking is the same, but the spooling buffer is not utilized.
COMPUTER-TO MODEL 24-TO-COMPUTER
When Computer A transmits data to Computer B through the Model 24,
the data is received from Computer A and stored in a 256-character
buffer which in turn retransmits it to Computer B. When there are only
15 bytes available in the buffer, the Model 24 will send an XOFF to
Computer A, signaling Computer A that it cannot accept more data.
When the Model 24 retransmits the data to Computer B, the Model 24
will expect to see a high on the CTS line or receive an XON. When
Computer B cannot receive any more data, the Model 24 will expect to
see a low on the CTS line or receive an XOFF.