Filter
Top Products
APPENDIX A – SCI PROTOCOL AND INTERFACE
A4
SPECIAL COMMANDS
There are several special commands
available that should be used with care.
COMMAND: SYSTEM HARD REBOOT
It is possible to force a system reset from the
serial port, duplicating the function of the RESET
switch on the front of the SCI. All outputs are
reassigned to source 1, all previously stored data
is cleared, all salvo information is erased, and the
system will then reboot as though a power-on
condition occurred. This hard reboot command is:
CTRL - C
Note no carriage return is required.
COMMAND: SYSTEM SOFT REBOOT
This is a less destructive reset. This method
will force the internal watchdog timer to restart the
system as though a power-on condition had
occurred. No crosspoint or salvo table information
is lost. Upon this reset the DIP switch settings of
the SCI are read. It is useful to use this reset
command when changing the DIP switches
without requiring a power down of the SCI. This
soft reboot command is:
CTRL - W
Again, no carriage return is required.
COMMAND: CONDENSED STATUS
It is possible to get the status of the system in
a condensed format. There are two possible
methods. The first is in binary and the second is in
packed BCD. The advantage here is a minimal
number of bytes are issued from the port and it is
a very efficient method of gaining the status from
within an external control program. Since these
characters may be non-printing ASCII characters
it is not useful to use in a terminal package.
The command for a condensed status in
binary is:
SB {RETURN/ENTER}
The command for a condensed BCD status
is:
SC {RETURN/ENTER}
For a detailed explanation of the byte
sequence please contact Sigma Electronics
software department.
COMMAND: HALT DATA TRANSMIT
The SCI supports the XON/XOFF protocol.
This is a method, through software, of halting and
resuming transmission of data. The XOFF is
activated by holding the Control key and pressing
'S' (CTRL-S). This will halt data transmission..
Incoming commands are still executed during an
XOFF. It is the responses generated by the SCI
that are not sent. They are held in a message
buffer until an XON is received. Like the CANCEL
command, XOFF is automatic and does not
require the RETURN/ENTER key to be pressed.
COMMAND: RESUME DATA TRANSMIT
XON is activated by holding the Control key
and pressing 'Q' (CTRL-Q). This will resume
transmission of data from the SCI. All pending
responses are sent out the serial port in the same
sequence in which they were received and stored.
Like the CANCEL and XOFF command, XON is
automatic and does not require the
RETURN/ENTER key to be pressed.
SALVO COMMANDS
The SCI-MRX is capable of internally storing
ten different salvos. A salvo provides a method of
switching multiple commands at one time. This
“grouping” of switches eliminates delay of
switching from the first step to the last step in a
multi-step switch. There are commands that
pertain exclusively to the creation, edit and
execution of a salvo.
The ten distinct Salvo symbols are as follows-
Symbol Keyboard Command
! Shift 1 Salvo 1
@ Shift 2 Salvo 2
# Shift 3 Salvo 3
$ Shift 4 Salvo 4
% Shift 5 Salvo 5
^ Shift 6 Salvo 6
& Shift 7 Salvo 7
* Shift 8 Salvo 8
( Shift 9 Salvo 9
) Shift 0 Salvo 10 (EAS)
SHIFT 1 through SHIFT 0 correspond to
salvo 1 through salvo 10. When activating a salvo
the first character in the command must be the
salvo designator symbol; !, @, #, $, %, ^, &, *, (,
or ). The Salvo stored as Salvo 10 will execute
upon a closure applied to the EAS screw
terminals on the rear of the master frame. This
provides an automatic response to an Emergency
Alert System alarm.