Dionex ICS-900 - Page 113

C • TTL and Relay Control
Doc. 065215-02 9/09 105
• Normal Edge: In normal edge
operation, the negative (falling) edge of
a signal turns on the function. For
example, for the
Load/Inject function,
the negative edge switches the injection
valve position to Load. For the
Pump
On/Off
function, the negative edge turns on the pump. For the Autozero
function, the negative edge performs an autozero command.
The action of the positive (rising) edge depends on the function. For example,
for the
Load/Inject function, the positive edge switches the injection valve to
the Inject position. For the
Pump On/Off function, the positive edge turns off
the pump. For the
Autozero function, the positive edge has no effect.
• Inverted Edge: The inverted edge mode
works identically to the normal edge
mode except that the positive and
negative edges are reversed in function.
• Normal Pulse: In normal pulse
operation, the negative edge of the TTL
signal is the active edge and the positive
edge is ignored.
A pulse width of 50 ms or more is
guaranteed to be detected. A pulse
width of 4 ms or less is guaranteed to be ignored. The action for pulse widths
that are greater than 4 ms and less than 50 ms is undefined.
• Inverted Pulse: The inverted pulse
mode operates identically to the normal
pulse mode except that the positive and
negative edges are reversed in function.
Action On
A
ction
Off
or No E
ff
ect
+5 V
+0 V
TTL
NORMAL
EDGE
Action
O
n
Action Off or No Effect
+5 V
+0 V
TTL
INVERTED
EDGE
Action On Action Of
f
+5
V
+0 V
TTL
NORMAL
PULSE
Action
O
nAction
Off
+5 V
+0 V
TTL
INVERTED
PULSE