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Ttrn Word
Buffer Channel (WBC)
The function of a word buffer channel is to transmit data to and receive data from another
DATANET-30 or a DATANET-600.
The word buffer can operate at the same standard bit rates as the character buffer. The bit
rate is established by a timing connector plug. The word length is not variable.
It
is established
at 18 bits for a DATANET-30 word, plus one parity bit and one control bit, giving a total of 20
bits per word.
This word length is established by a 20-bit code level connector. The DATA-
NET-600 word is similarly established at 14 bits.
THE RECEIVE PARALLEL UNIT BUFFER MODULE
The receive parallel unit buffer module can contain 1 or 2 receive parallel units (RPU). Each
unit receives information from one communications channel.
Each RPU has a control section.
The buffer selector address for each channel (RPU) is specified by the address plug for the
module and each RPU is addressed independently of the other. The code level for each RPU
may be different.
The Receive Parallel Unit
The
receive parallel unit provides buffering, on a receive-only basis, for one character of
information in any parallel code up to a 14-channel code level. The RPU buffers the input
from a local DATANET-3101 with an 8-level code. A timing connector plug is not used. The
upper limit of speed of transmission (receiving information) is determined by the scan rate
of the program and should be consistent with the system rate. Operation is asynchronous,
timed by the transmitting device.
data lines
DAT ANET
I
I
3101
I
I
ACCUMULATOR
2 control lines
Receive Parallel
Unit
data lines
i
T
_i
l
2 control lines
Figure 2. The Receive Parallel Unit with the DATANET-3101
Receive Sequence
DAT ANET
30
COMMUNICATION
PROCESSOR
The RPU and the DATANET-3101 accumulator are directly connected (on line at all times).
When no signals are present on the line, the receive flag is not set and the program ignores
the buffer.
When a character is received, the receive flag is set and the program must take
the character before the next one is transmitted.
[ID&u&~~uc:J ~@------------
I-4
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