Hall Research VSM-404 User Manual
Page 12
Model VSM-404
10
3.7 Control from Serial Devices (RS-232 Command Protocol)
To control the Video Matrix Switch through an attached PC or other serial
device, the serial device has to be able to communicate with the Switch.
(You’ll need to set the device to 1200 bps, 8 data bits, and no parity; the
number of stop bits is irrelevant.).
To tie the unit to a PC, use a DB9 F/F cross-over cable (Null Modem:
2<>3, 4<>6, 7<>8, 5=5).
The serial device will have to mimic the Switch’s keypad commands.
When you press a button on the keypad, a “make” code is sent to the
Switch; when you release a button, a “break” code is sent to the Switch.
Here are the values you need to send to the Switch to get it to change
channels, listed as both ASCII characters and hexadecimal values:
Make Code
Break Code
Keypad
Button
ASCII
(HEX)
ASCII
(HEX)
1
`
(60)
@
(40)
2
a
(61)
A
(41)
3
b
(62)
B
(42)
4
c
(63)
C
(43)
5
d
(64)
D
(44)
6
e
(65)
E
(45)
7
f
(66)
F
(46)
8
g
(67)
G
(47)
9
h
(68)
H
(48)
0
o
(6F)
O
(4F)
+
m
(6D)
M
(4D)
-
l
(6C)
L
(4C)
.
n
(6E)
N
(4E)
*
k
(6B)
K
(4B)
/
j
(6A)
J
(4A)
Esc
i
(69)
I
(49)
Enter
t
(74)
T
(54)
NumLock
y
(79)
Y
(59)
LEFT
z
(7A)
Z
(5A)
TAB
{
(7B)
[
(5B)
SHIFT
|
(7C)
\
(5C)
Fn
}
(7D)
]
(5D)