DESCRIPTION AND OPERATION
FUNCTIONAL BLOCK DIAGRAM
2 - 2
I-E96-310B
®
close them. The relays follow the output of the registers. Dur-
ing normal operation, the DSO module selects the output reg-
ister data. Its outputs also turn the front panel output status
LEDs on or off. A logic one is inverted by the output block cir-
cuits to energize a relay and light an LED. A logic zero de-ener-
gizes a relay and turns an LED off.
Figure 2-1. Digital Output Module Block Diagram
Figure 2-2. Digital Output Circuit
TP21193A
I/O EXPANDER BUS
I/O EXPANDER BUS
INTERFACE
ADDRESS
DIPSWITCH
I/O EXPANDER BUS
FAULT DETECTOR
MODULE
STATUS
MODULE
STATUS LED
OUTPUT
REGISTER
DEFAULT
REGISTER
STATUS
BUFFER
DATA
SELECTOR
DEFAULT
CONTROL LOGIC
DIGITAL
OUTPUT
DIGITAL
OUTPUT
STATUS LEDs
FUSE STATUS
DETECTOR
FUSE
STATUS
LED
DIGITAL OUTPUTS
+
-
+
-
+5 V
+5 V
+5 V
FROM OUTPUT
CIRCUITRY
+5 V
+
-
+5 V
+5 V
FIELD
OUTPUT
+
-
TO FUSE BLOWN
INDICATOR
CIRCUITRY
TP27122A
SOLID
STATE
RELAY
