Hybrid Analog Output - Johnson Controls Penn System 450 Series Technical Bulletin

Each time a System 450 module assembly is powered on, the control module polls
all of the modules to identify output type (relay or analog) and then assigns an
output number (1 to 9 and 0 = 10) to each output, starting with the first output on
the first expansion module connected to the right of the control module (Figure 4).
Output numbers are displayed on the control module LCD to identify the output
you are viewing as you navigate the system status and setup screens in the
System 450 UI (Figure 2).

Hybrid Analog Output

The C450CPW-100 control module is designed for use with variable speed
Electronically Commutated (EC) fan motors on a wide variety of refrigeration and
HVAC condensing units.
The C450CPW-100 module has a single onboard analog output that can be
configured as a hybrid analog output to optimize and extend the controlled speed
range of variable speed EC motors. The onboard analog output can also be set up
for High Input Signal Selection, which enables precise and efficient EC motor
speed control on multi-circuit condensing units.
Hybrid analog output control enables the C450CPW-100 control module's hybrid
analog output to transition between a pulse output and a standard VDC output,
depending on the sensor value relative to the proportional band. At low output
levels, the pulse output signal provides an average motor speed that is less than the
EC motor's fixed minimum speed (Figure 5).
Figure 5: Pulse Signal with Pulse Level = 25% and Logical Output = 12.5%
Note: Only Analog Output 1 (OUTA1) on the C450CPW-100 control module can
be configured as a hybrid analog output and use the High Input Signal
Selection feature. These features are not available for any of the other
outputs in control systems that use a C450CPW-100 control module.
14 System 450™ Series Modular Control Systems with Standard Control Modules Technical Bulletin