Patton electronic 3060/V24 - Manual (Page 7)

3060/V24
102001UA
1-3 O PERATION
P ATTON E LECTRONICS C O . I NSTALLATION A ND O PERATIONS M ANUAL
Channel Selection Modes
The Patton 3060/V24 (MD-V.24/TCB) provides two selectable Sub-Channel service modes of
operation, the Scanning Mode and Priority Mode. Depending on system requirements, either
mode may be selected by internal DIP switch settings. Both modes switch on activity from the
Sub-Channel.
In the Scanning Mode the Patton 3060/V24 (MD-V.24/TCB) scans each Sub-Channel, in
sequence, beginning with Sub-Channel 1. This rotational sequence is repeated continually
with each attached Sub-Channel having equal access to the communications link. When data
or control lines from a Sub-Channel become active that Sub-Channel is switched through to
the master port by the 3060/V24 (MD-V.24/TCB). All remaining Sub-Channels are locked out
until the first device becomes inactive. When the Sub-Channel device becomes inactive, the
3060/V24 (MD-V.24/TCB) will resume scanning the Sub-Channels for another active signal.
When configured for Priority Mode operation, the Patton 3060/V24 (MD-V.24/TCB) monitors
all Sub-Channels simultaneously with Sub-Channel 1 having the highest priority. When a Sub-
Channel becomes inactive, the 3060/V24 (MD-V.24/TCB) will automatically default to the
highest priority (lowest number) Sub-Channel with activity.
Contention for the Master port is accomplished by asserting RTS (Request to Send) if the
Sub-Port is configured as a DCE, DCD (Data Carrier Detect) if the Sub-Port is configured as
a DTE or Data Transitions from the attached Sub-Channel devices in either configuration. The
active interface lead, RTS or DCD, as well as selection of contention mode,
“Data Transitions”
or “Interface Lead” activation, can be selected on an individual basis for each Sub-Channel.
Once a Sub-Channel asserts an active control signal the control signal will be passed through
to the Master Port, depending on DTE / DCE configuration of the Sub-Channel and Master
Port. This control will be passed without delays. If the Master Port is configured as a DTE the
signal will be passed as RTS. The CTS returned to the Master will have an optional delay
added before the signal is returned to the Sub-Channel port.
Port Enable / Disable, front panel switches must be pushed in (GREEN indication) for a Sub-
Channel to access the Master Port regardless of the mode of operation selected.