LINKUP 5294 WITH DL5294 FIRMWARE
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HALF-DUPLEX (DCE) —
Following data reception from the host, the LinkUp 5294 waits for the
Request-To-Send signal to go low before raising the Carrier.
•
FULL-DUPLEX (DTE) —
Following data reception from the host, the LinkUp 5294 immediately
raises the Request-To-Send signal.
•
FULL-DUPLEX (DCE) —
Following data reception from the host, the LinkUp 5294 immediately
raises the Carrier Detect signal and starts transmission.
NOTE
The LinkUp 5294 raises and lowers RTS under a DTE interface and CD under a DCE
interface during Full Duplex operations because it is an essential procedure in multi-
point applications; for example, a Control Unit on a multi-point line, which does not
lower its RTS signal at the end of a transmission, prevents the other Control Unit(s)
from ever using the line. The host’s communication adapter should be set so its RTS
signal is permanently raised.
5. NRZI Encoding
Valid values are YES or NO.
The appropriate value here depends on your host’s requirements. Normally, a System/3X is strapped for
NRZI encoding (specify YES); if not, the LinkUp 5294 is able to support direct encoding (specify NO).
6. Emulation Mode
Valid values are: 5251 (IBM 5251 Model 12 Remote Workstation Controller), 5294 (IBM 5294 Remote
Cluster Controller), or 5394 (IBM 5394 Remote Cluster Controller).
NOTE
The 5294 and 5394 emulation modes do not support all of the actual IBM 5294 or 5394
Controller functions. For example, Text Write Assist is not supported. Consult your
supplier for further information on these limitations.
7. Number of Link Stations
Valid values are: 0 through 4. This parameter dictates how many Link Station Addresses will be
recognized by the LinkUp 5294 on this port; that is, how many controllers will be emulated by the
LinkUp 5294 through this port. The addresses of these controllers are then specified in parameters 8
through 11, below. Values greater than one are valid on deluxe units only.
NOTE
A maximum of four Link Station Addresses may be specified on the two synchronous
ports, in any combination. If a value for this parameter is specified so that this
maximum is exceeded, the following error message is displayed:
7: VALUE OUT OF RANGE; TOTAL NUMBER OF LINK STATIONS FOR PORT 0 AND
PORT l IS 4.
When the value of this parameter is lessened, Link Addresses (in parameters 8 through
11) which fall outside the valid range are automatically set to 0; for example, if
parameter 7 is set to 0, parameters 8 through 11 will also be set to 0, and no controllers
can be emulated on that port.