Intelligent Motion Systems Modular LYNX System - Manual (Page 32)

1 - 32 Modular LYNX System 12.05.2003
C o n f i g u r i n g T h e D i f f e r e n t i a l I / O - T h e I O S V a r i a b l e
The high speed differential I/O is configured by means of the IOS variable, and is used in the the same
fashion in which the isolated I/O is configured. The main difference lies in that there are three additional
parameters which need to be set in configuring the triggering, clock type, and ratio mode setting.
It is important to note that the high speed differential I/O lines may be used for the same input or output functions
as the isolated digital I/O where the higher speed capabilities of the differential I/O is required. However, for
purposes of this example we will only illustrate the clock functions associated with the high speed differential I/O.
Figure 6.5 following illustrates the IOS variable settings for the high speed differential I/O.
Figure 6.5: IOS Variable Settings for the High Speed Differential I/O
IOS = , , , , , X X X X X X X X
Enter the Channel # (13-18) here!
Enter I/O Line Type # Here
1 = Clock 1A
2 =
3 =
4 =
5 =
6 =
7 =
8 =
Clock 1B
Clock 2A
Clock 2B
Clock 3A
Clock 3B
Clock 4A
Clock 4B
Define Line or Group
As Input or Output
0 = Input
1 = Output
Define the Clock Type
0 = Not A Clock
1 = Quadrature
2 = Step/Direction
3 = Up/Down
Set the state
of the Line or Group
0 = Active Low
1 = Active High
Set the Ratio Mode
0 = No Ratio
1 =Ratio Set the Triggering
0 = Level
1 = Edge
NOTE: The
Clock #’s are
fixed to their
associated I/O
channel and
cannot be
changed! They
are entered for
sake of consistency
only!
C o n f i g u r i n g a n I n p u t
Clocks 2, 3 and 4 can be configured as high speed inputs, or as a general purpose input in the same fashion
as the Isolated I/O. In configuring the Differential I/O line as a general purpose input you would typically
use the “+” line of the line pair. You cannot use both lines as separate I/O lines. The figure below shows the
Input Equivalent Circuit with the I/O line pair connected to channel A of a differential encoder. This feature
Figure 6.6: Differential I/O Input Equivalent Circuit
Input (+)
Channel A (+)
Differential
Encoder
Channel B (+)
Index (+)
Channel A (-)
Channel B (-)
Index (-)
Input (-)
+5VDC
Digital
Filter
Polarity
Edge
Level
Edge
Detect
Logic
Group
Filter
Setting
H
igh
S
p
e
ed Di
ff
ere
n
ti
a
l I
/O
M
odule
10k
Ω
4k Ω
3.3k
Ω
20k Ω
+
-
4.3V
1.4V