DTE(terminal type) equipment. Refer to the interface chart in the Appendix for detailed
interface information.
2.5 SUB-CHANNEL SERVICE MODES
The MSD-4C unit incorporates circuitry that enables the user to provide two separate
modes of DTE sub-channel access servicing. Either mode of operation is selected
upon installation via a Dip Switch located inside the housing located at
SW1-4
. The
user may select
TEXT
or
GRAPHICS
mode of operation.
2.5.1 TEXT MODE
In the
Text Mode
, the MSD-4C will enter switch-time whenever it receives an arming
character. It will select the sub-channel that is specified by the channel select ASCII
character. The remaining text will pass through the unit until another arming character is
encountered. The arming character and the sub-channel select character will not pass
through the unit in this mode. The user should make certain that the arming character
that will never appear as part of the text.
2.5.2 GRAPHICS MODE
The
Graphics Mode
is capable of passing graphics data while still maintaining code
control. In this mode, an arming character will only be recognized as an arming
character if it is preceded by a pause in data transmission of a minimum length of time
of
100 milliseconds of No Data
.
(other options available)
2.5.3 PASSED OR FORCED CONTROL SIGNALS
The MSD-4C has several user defined options for passing or forcing control signals.
Please refer to the
Strap Chart
in the Appendix.
2.6 ANTI-STREAMING
2.6.1 AUTOMATIC DTE REMOVAL
The MSD-4C incorporates circuitry that will (when enabled)
automatically
remove a
streaming sub-channel from service. A streaming terminal is defined as a terminal that
has been active longer than the user predefined anti-stream timer has been set. Upon
installation, the user can set or actually fine tune the timer to your network
requirements. Each channel has a Green and a Yellow LED to indicate sub-channel
activity. Green indicates an active sub-channel and Yellow indicates a streaming
sub-channel. Once a terminal has gone into the streaming condition (sub-channel
active too long) the DTE will automatically be removed from service until the DTE fault
has been corrected by the user. All other DTE's will continue to be serviced by the
MSD-4C.
MSD-4C INSTALLATION AND OPERATIONS MANUAL
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