Rockwell Automation 1769-OF4 Compact Analog Output Module - Manual (Page 11)

Publication 1769-UM020A-EN-P - December 2009 11
Overview Chapter 1
System Overview The module communicates to the controller through the bus interface.
The module also receives 5 and 24V DC power through the bus
interface.
You can install as many analog modules as your power supply can
support. However, the modules may not be located more than eight
modules away from the system power supply.
Determine Power Supply Distance
Module Operation When you cycle power, the module performs a check of its internal
circuits, memory, and basic functions. During this time, the
module-status OK indicator remains off. If no faults are found during
power-cycle diagnostics, the module-status OK indicator is turned on.
After power-cycle checks are complete, the module waits for valid
channel-configuration data. If an invalid configuration is detected, the
module generates a configuration error. Once a channel is properly
configured and enabled, the module begins its conversion process.
Each time a new output value is sent to the module, it is tested against
user-configured high and low output clamps for each output channel.
If output values equal to or exceeding either of these clamp levels are
detected, the value sent to the module is clamped at that limit by the
module, and unique bits are set in the output-channel status word.
1
1 1 2 3 4 3 2
2 3 4
System Power Supply
Compact I/O Compact I/O Compact I/O
En
d Ca
p
CompactLogix
Controller
or I/O
Commu
nicat
io
n
Ad
ap
te
r
Compact I/O Compact I/O Co
m
pa
ct
I/
O
or
Power Supply Distance
Compact I/O Compact I/
O
Compact I/O Compact I/O
En
d Ca
p
MicroLogix 1500 Controller
with Integrated System
Power Supply
Power Supply Distance