6100 BSC Programming Manual

Features of the 6100 BSC Product
Other important features of the BSC module are:
• BSC supports a single point-to-to-point link.
• The maximum data rate on a link is 19200 bits per second.
Either the modem or the LIU can supply the transmit clock.
• The message formats are those specified in the IBM manual
defining the protocol, with the following exceptions: BSC
doesn't check for pad characters after an EOT or NAK
sequence, nor does the receiver look for a SYN to occur
at three-second intervals. BSC does, however, transmit
a pad after an EOT or NAK, and places two SYN characters
(or DLE SYN) in the output stream every second.
• There is no provision to send leading graphics before an
ACK or NAK sequence. If a remote station sends such
graphics--up to seven characters--BSC discards them.
• An LIU running BSC can be a primary or a secondary station.
A point-to-point link should have one primary and one
secondary station, although the protocol does not forbid
a link with two primaries or two secondaries.
• The electrical interface must be RS-232.
• You can specify ASCII to EBCDIC translation for outgoing
data, and EBCDIC to ASCII translation for incoming data.
An application can supply its own translation tables for
input and output.
• You can use either switched or leased lines, and either
half or full duplex modems. Line turnaround is controlled
by the Request-to-Send/Clear-to-Send delay of the modem.
• Multiple processes can have the line open concurrently.
On the other hand, only one request can pending at a time.
(A few exceptions exist: namely, requests that retrieve
statistics or configuration data, and the ABORT request.)
• You can choose either CRC16 or LRC/VRC block checking.
• ID exchange on connection is optional.
• A station may make a conversational reply after receiving
a conversational reply. Most devices that use BSC protocol do
not support this feature.
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