Sierra Video 503108 RS-232 User Manual

1

Sierra Video Systems • P.O. Box 2462 • Grass Valley, CA 95945 • [phone] • Fax [phone]

503108 RS-232 INTERFACE

Contents

Installation ....................................................................................... Page 2

Control via a terminal ...................................................................... Page 3

Control via a host computer............................................................. Page 4

RTRCTRL, a DOS program ............................................................ Page 9

Circuit description of the 503108 module...................................... Page 10

Parts list for the 503108 module .................................................... Page 12

Schematic diagram of the 503108 module..................................... Page 13

Component location drawing of the 503108 module..................... Page 14

Warranty registration card.............................................................Attached

A 3" floppy disk including RTRCTRL and its source code..........Attached

2

Sierra Video Systems • P.O. Box 2462 • Grass Valley, CA 95945 • www.sierravideo.com

503108 RS-232 INTERFACE

S1-3 on = send switch changes as “X”

messages as other controllers
alter router

S1-3 off = only respond to inquiries from

host

The 503108 is shipped with S1-3 in the on position.

S1-4 on = send XON / XOFF to host if

buffer fills

S1-4 off = do not send XON / XOFF

The 503108 is shipped with S1-4 in the on position.

S1-5 on = host mode
S1-5 off = terminal mode

The 503108 is shipped with S1-5 in the on position.

An 8 position DIP switch inside the module (S2)
sets the system size.

S2-1,2,3 Levels
1 Level =1 off 2 off 3 off
2 Levels = 1 on 2 off 3 off
3 Levels = 1 off 2 on 3 off
4 Levels = 1 on 2 on 3 off
5 Levels = 1 off 2 off 3 on
6 Levels = 1 on 2 off 3 on
7 Levels = 1 off 2 on 3 on
8 Levels = 1 on 2 on 3 on

S2-4,5,6 Number of outputs
8 Outputs = 4 off 5 off 6 off
16 Outputs = 4 on 5 off 6 off
24 Outputs = 4 off 5 on 6 off
32 Outputs = 4 on 5 on 6 off
40 Outputs = 4 off 5 off 6 on
48 Outputs = 4 on 5 off 6 on
56 Outputs = 4 off 5 on 6 on
64 Outputs = 4 on 5 on 6 on

S2-4,5,6 are not used on 12 input systems

S2-7 on = 12 input systems
S2-7 off = 8 or 16 inputs
S2-8 must be off off for 12 input systems
S2-8 off = 8 inputs
S2-8 on = 16 inputs

INSTALLATION

The RS-232 serial control option is normally
installed at the factory. If the 503108 module is
ordered separately, it should be plugged into the
left-most position in the router frame. In multi-frame
systems, the 503108 can be installed in any frame.

Serial connections. Connection is via a 9 pin
female D connector on the rear of the frame. The
pin connections for this connector are as follows:

Pin 1 Ground
Pin 2 Transmit - output (to receive - input)
Pin 3 Receive + input (to transmit + output)
Pin 4 Ground
Pin 5 No connection
Pin 6 Ground
Pin 7 Transmit + output (to receive + input)
Pin 8 Receive - input (to transmit - output)
Pin 9 Ground

When used for RS-232C control, pins 3 and 7 are
not connected.

The 503108 is normally configured at the factory
for RS-232 interface. RS-232 is also available. It
is possible to change from RS-232 to RS-422 (or
RS-422 to RS-232) in the field. Refer to the circuit
description for additional details and contact SVS
to obtain the required parts.

The 503108 has two DIP switches. A 5 position
DIP switch on the front edge of the module (S1)
sets the data rate and communication mode. The
settings for S1 are as follows:

S1-1,2 communication speed

1.2K Baud = 1 off 2 off

9.6K Baud = 1 on 2 off

38.4K Baud = 1 off 2 on

115.2K Baud = 1 on 2 on

The 503108 is shipped set to 9600 baud.

3

Sierra Video Systems • P.O. Box 2462 • Grass Valley, CA 95945 • [phone] • Fax [phone]

503108 RS-232 INTERFACE

The line beginning with “OUT” lists all of the
outputs that are available. In this example, the
router has 16 outputs. Following this line is one
line for each level. In this example, the router has
2 levels. Each level line shows the inputs which
are connected to outputs at that level. In the
example, input 5 is connected to output 2 on level
1, input 21 is connected to output 6 on level 1, and
input 1 is connected to output 3 on level 2.

The next line reminds the user that this status
display can be re-displayed at any time by pressing
the “ESC” (ESCAPE) key on the terminal.

The next line, “OUTPUT -: ”, is a prompt which
is requesting the user to enter an output number.
The number can be entered as either 1 or 2 decimal
digits between 1 and the number of outputs
available. CR (CARRIAGE RETURN) must be
pressed after the digits have been entered. If a
number is entered that is out of range, the status
display is re-displayed and the output prompt
appears again.

After an output number is entered, the “INPUT -:”
prompt appears for an input number. Again, 1 or 2
decimal digits must be entered, between 1 and the
number of inputs available, followed by CR.

Finally, a prompt appears for a level number. Two
options are available at this point. Pressing CR
without entering a number causes a connection to
be made between the input and output on every
level (referred to as AFV). Alternatively, one
decimal digit may be entered for the level number,
followed by ENTER. This results in a connection
made between the input and the output on that
level only.

The ESCAPE key may be pressed at any time to
abort the current input and start over.

The BACKSPACE key may be pressed to erase a
digit just entered.

TERMINAL CONTROL

The 503108 can be used in either a HOST or
TERMINAL mode. When used in the terminal
mode S1-5 must be in the off position. Most
commonly available terminals will work. Termi­nals usually have either a setup screen or a DIP
switch to set the communications mode. The
following communication characteristics should
be set for the terminal:

9600 baud
8 data bits
no parity
one stop bit
(total per ASCII character is 10 bits)

Each time the router is powered up, or a DIP
switch on the 503108 is changed, the 503108 will
go through a reset cycle. This takes about 20
seconds. At the end of the reset cycle the 503108
will scroll the terminal screen and display a reset
message. The message includes the type and size
system. A typical reset message is:

Sierra Video Systems

Series 16 Router
V1.14 (C) 1990-1994
8 IN X 8 OUT X 4 LVL
DO NOT Send XON/XOFF Host Control: OFF
Press any key to continue.

The above message will vary depending on the
settings of S1 and S2 as described earlier. After
the reset screen comes up the operator must push
a key to cause an inquiry to the 503108 which
results in a screen which displays the entire status
of the router. Along the bottom of the status
screen is the interactive area where the operator
can make switch changes within the router. The
contents of this area of the screen are as follows:

Press “ESC” to display status
Output - :3
Input - :12
Level (press “CR” for AFV) - :1

4

Sierra Video Systems • P.O. Box 2462 • Grass Valley, CA 95945 • www.sierravideo.com

503108 RS-232 INTERFACE

The terminal protocol echoes each digit character
that is entered, so the terminal should be set so that it
does NOT echo characters as they are pressed.

HOST COMPUTER PROTOCOL

The protocol is designed to use the 7 bit ASCII
character set (00-7F hex), usually sent over a
RS-232C or RS-422 serial link. The high- order
data bit is ignored on all received characters, and
is 0 on all transmitted characters.

The protocol is designed for use over a reliable
channel. Noisy channels such as modem connec­tions over the telephone network should use an
error-checking and/or error-correcting protocol,
including such things as packet checksums or
CRC’s. Newer modems include such communica­tion schemes as part of their normal operation,
and are recommended for these applications.

The protocol is designed to be compact, with few
characters required to cause switch changes to
occur. It is also designed to be human-readable
and thus easy to understand and use. Finally, it is
a modified superset of the existing SVS host
protocol, allowing a degree of compatibility with
those existing systems.

Several different switch request commands are
defined, so that the one that is most compact for
any given switcher and application can be chosen.

The protocol is designed to be useful with both
very small and very large routing switchers. The
sizes of the numbers representing inputs, outputs,
and levels are not fixed, but can be as large or small
as necessary. Special provisions allow numbers to
be packed one after another with no intervening
delimiter character, in order to make the protocol
compact, as long as each number is the largest
size necessary for that particular switcher.

All input, output, and level numbers begin at
number 1, not 0.

Commands are sent to a routing switcher in a
group called a command string. A command
string can contain zero or more commands,
limited only by the size of the receive buffer of
the switcher, which should be large enough to
hold a command string for setting the state of the
entire switcher matrix.

A command string consists of a leader, zero or more
commands, and a trailer. If a leader character is
encountered within the command string, the
command string up to that point is discarded and a
new command string is started. Once a complete
command string, up to the trailer character, is
received, the routing switcher executes the com­mands within it.

Within the command string, certain ASCII charac­ters may be present and are ignored: any ASCII
character whose code is less than or equal to the
SPACE character, and any whose code is greater
than the “~” (tilde) character. Alphabetic characters
within the command string may be in either
uppercase or lowercase letters.

Just before the switcher begins executing a com­mand string, it sends a leader character to the host.
As it executes the commands, some of them may
generate additional output back to the host. After
the command string has been executed, the routing
switcher returns the string “OK” (with a single
space character before and after the word “OK”),
followed by a trailer character (~) and a CR
character, to the host This indicates that the
command has executed successfully. If an error
occurs within any command of a command string,
the remainder of the command string is ignored
and the switcher returns the string “ERROR”,
followed by a trailer character and CR character,
to the host. An error consists of an unknown
command name or bad arguments to a command.