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ADDR FUNCT switch is OFF, the filtering action applies
only to CCL data. See Table 1.
S103 and S104 are the Address select DIP switches. See
Table 2. These switches apply only if the MATCH switch
(S102-4) is ON. The Address DIP switches are used to set
a value which would be compared against the incoming CCL
data (when S101-4 is OFF) or receiver/driver data (when
S101-4 is ON). Only that data which corresponds to the
value set via the Address DIP switches would be
transmitted. When used as a Satellite Selector Unit in an
Allegiant Satellite configuration, the Address DIP switches
are used to set the Satellite's address so that only CCL
commands associated with the Satellite would be
transmitted. See Table 4. When the LTC 8780 is
configured to pass satellite commands, it also automatically
passes the "Synchronize Satellite Time/Date CCL command.
The "Synchronize Satellite" command is a unique CCL
command selected in the Time Event table found in the
Allegiant Master Control Software package or the TC8850
Graphical User Interface (GUI) software. It is used to
synchronize the time and date of all satellite locations to the
time and date as generated by the main Allegiant system. If
desired, the LTC 8780 can selectively pass Allegiant
"Synchronize Satellite Time/Date commands by configuring
the unit in the Satellite Selector mode, but setting the site
address to 256 (all S103 and S104 switches to ON). In this
configuration, the LTC 8780 can be used to generate
time/date commands for interfacing to other non-Allegiant
products.
The Address select DIP switches can also be used to limit
the amount of transmitted receiver/driver commands so
that only data within a block of 64 addresses that
correspond to the value set via the Address select would be
transmitted. See Table 5. This filtering action feature for
receiver/driver data outside of a block of 64 addresses
might be necessary in larger switcher configurations where
only a slow RS-232 baud rate is available. If MATCH is OFF,
no address/block matching is done and the Address DIP
switches are ignored. The Address select DIP switches use
a binary progression format to determine their value, i.e., all
switches OFF represent a value of 0, while all switches ON
represent a value of 255. The DIP switch settings and the
equivalent values are shown in the CCL Address Select and
the Receiver/Driver Block Select tables.
DIP Switch S105, labelled "MODEM CMD", controls
various features which are used to define how the RS-232
interface will operate. These features are described in the
paragraphs below. Refer to Table 3.
Switch S105-1, labelled "MODEM CMD", controls the
operation of the ORIGINATE feature switch (S105-2)
described below which is available to assist in making a
connection using modems compatible with the "AT"
command set. If any other type of interface is being used,
this option should be disabled by setting switch S105-1 to
OFF. See Table 3.
Switch S105-2, labelled "ORIGINATE", is active only when
S105-1 is set to ON (MODEM CMD), and should be set
according to the following guidelines. See Table 3.
"AT" COMMAND COMPATIBLE MODEMS WITH
DIRECT CONNECTION
In this context, a "direct connection" means that it is
not necessary to dial a phone number to connect the
modems. In this case, the LTC 8780 units are
configured so that one issues the answer command
"ATA", and the other issues the originate command
"ATX1D". The MODEM CMD switch (S105-1) should
be set to ON on both units. The ORIGINATE switch
(S105-2) should be set to ON in the LTC 8780 being
used as the originating unit and OFF in the unit being
used as the answering unit. After power on, the units
will delay for 30 seconds (to allow sufficient time for
modem initialization) before sending any RS-232 data.
The LTC 8780 units can be powered on in either
order, but steps should be take so that no RS-232 data
is sent until the connection is made. This can be
assured by either turning off or disconnecting the
biphase code input source until the connection is made.
"AT" COMMAND COMPATIBLE MODEMS WITH
PHONE-LINE CONNECTION
This procedure can be used to establish a connection
over a standard telephone line. In this case, one of the
phone modems must be set to the Auto-Answer mode
(see the modem instructions to configure this). The
LTC 8780 unit connected to the auto-answer modem
should have the MODEM CMD switch (S105-1) set to
OFF. At theoriginating end, the MODEM CMD and
ORIGINATE switches (S105-1 and S105-2) should both
be set to ON. Begin with the originating LTC 8780 unit
turned OFF. With the modems on and ready, dial the
phone number for the answering unit. After the
answering modem answers, power on the originating
LTC 8780 Series unit. The originating unit provides a
30 second delay to allow for the modem connection to
be made. No RS-232 data should be sent until the
communication link between the modems is made. If
the modem connection takes longer than 30 seconds,
the biphase code input source should be either turned
off or disconnected until the connection is made.
Switch S105-3, labelled "CHECK CTS", provides an
option for activating the LTC 8780 unit's RS-232 interface
CTS handshake feature. The LTC 8780 unit is always ready
to accept data, therefore the RTS and DTR handshake lines
are always active. If the CTS DIP switch is ON, the
LTC 8780 Series will transmit RS-232 data ONLY when the
CTS signal is asserted. If the CTS DIP switch is OFF, the
state of the CTS is ignored, and data will be transmitted
freely. See Table 3.
The LTC 8780 CONSOLE connector is only intended to be
used for transmitting data to an Allegiant system
CONSOLE port when used in a Satellite Selector con-
figuration. When connected in this fashion, the Allegiant
CONSOLE port must be configured with handshake turned
OFF. When the Allegiant handshake is OFF, it does not
check its own CTS line before transmitting, but it still
generates its RTS output. It is therefore recommended
that the LTC 8780 CHECK CTS switch (S105-3) is
turned ON, and it is mandatory that the Allegiant is
configured with its Handshaking turned OFF.
It is not necessary to utilize handshake lines if the LTC 8780
is being used with a LTC 5112 Series or LTC 5124 Series
switcher operating in a satellite configuration. In this case,
the LTC 8780's CTS DIP switch should be turned OFF.
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