Emerson DL8000 - Page 49

DL8000 Preset Instruction Manual
Revised February-2016 Modules 3-11
The DI module provides a source voltage for dry relay contacts or for an
open-collector solid-state switch.
The DI module’s LEDs light when each input is active.
You can configure each DI channel to function as a momentary or
latched DI (see the ROCLINK 800 Configuration Software User
Manual) (for DL8000) (part D301259X012). A latched DI remains in
the active state until reset. Other parameters can invert the field signal
and gather statistical information on the number of transitions and the
time accumulated in the on-state or off-state.
Caution
The Discrete Input module operates with non-powered discrete devices,
such as “dry” relay contacts or isolated solid-state switches. Use of the
DI module with powered devices may cause improper operation or
damage.
The DI module senses the current flow, which signals the electronics in
the DL8000 that the relay contacts have closed. When the contacts open,
current flow interrupts, and the DI module signals the electronics in the
DL8000 that the relay contacts have opened. A DL8000 can read a DI a
maximum of 250 times per second.
The left side of Figure 3-9 displays the internal circuitry while the right
side of the diagram displays possible field wiring.
+
-
DRY CONTACT
ROC800 POWERED
+
-
+V
6.6K
W
DOC0507A
C
O
M
6
8
7
4
5
3
2
1
DI
8
C
HAN
OPEN DRAIN TYPE DEVICE
OR
OPEN COLLECTOR
EXTERNALLY POWERED
Figure 3-9. Discrete Input Module Field Wiring
Caution
You can induce ground loops by tying commons from various modules
together.