Relay Output Control; Output Types; Tri-State Modulating; Analog - Trane Tracer MP501 Installation, Operation And Maintenance Manual

Relay Output Control

Binary output 3 (relay output) energizes whenever the PID loop is enabled (refer to the previous
section,

Output Types

The controller is configurable to control the other outputs in one of three ways:
•
•
•

Tri-state Modulating

The tri-state modulating actuator uses two TRIAC outputs to drive the actuator either farther
opened or farther closed. The controller takes the PID output of 0 to 100% and then decides which
way to drive the actuator. If it should be opened farther, the controller determines how much time
to turn on the open binary output in order to reach the desired position. Similarly, if the PID loop
calculates that it should be closed farther, the controller determines how much time to turn on the
close binary output in order to reach the desired position. The output defaults to 50%. Overdrive
logic automatically calibrates the actuator at the fully open and closed positions without
continually driving the actuator. This can cause unnecessary wear.

Analog

The controller takes the PID output of 0 to 100% and scales it for the analog output. For example,
if the analog output is configured as a 2–10 Vdc actuator when the PID calculates a value of 50%,
the controller scales it and then the analog output goes to 6 Vdc. The minimum and maximum
outputs of the analog output are configurable. For example, when a 6–9 Vdc actuator controls a
valve where the 9 Vdc closes the valve and the 6 Vdc opens the valve. In the configuration for the
analog output, enter 9 Vdc for a PID output of 0% and 6 Vdc for a PID output of 100%.

2-stage

In this mode the controller takes the PID output of 0 to 100% and turns on binary output 1 when
the PID output exceeds 30%. Binary output 2 comes on when the PID output exceeds 70%. Binary
output 2 goes off when the PID output drops below 45%. Binary output 1 goes off when the PID
output drops below 5%. See Figure 12.
Figure 12. Make and break limits for 2-stage

PID Control

This section provides information about
CNT-SVX08F-EN
"Loop Enable/Disable," p.
Tri-state modulating
Analog
2-stage
O
u
Active
t
Stage 2
p
u
Inactive
t
Active
S
Stage 1
t
a
Inactive
t
e
28). It is de-energized whenever the PID loop is disabled.
Make Make
Limit 1
Limit 2
30%
70%
Break Break
Limit 1 Limit 2
5% 45%
Actuator Command (Percent)
29