Sequence Of Operations For Generic Mode; Power-Up Sequence; Loop Enable/Disable - Trane Tracer MP501 Installation, Operation And Maintenance Manual

Sequence of Operations for Generic Mode

Sequence of Operations for Generic Mode
Configuring the MP501 in generic mode will control a variety of applications. The MP501 controls
a process based on an input that is one of the following:
•
•
•
•
•
Note: The generic mode applications do not follow a LonMark profile.

Power-up Sequence

When 24 Vac power is initially applied to the MP501, the following sequence occurs:
10. The Status LED goes on.
11. All the outputs are turned off.
12. The controller reads all the inputs to determine their initial values.
13. A user-adjustable (power-up control wait) delay timer begins. If set to less than 10 seconds, a
14. The Status LED goes off.
15. The delay timer expires.
16. The Status LED goes on.
17. If a hardwired input (4–20 mA) is not detected and no value has been communicated, the
18. Normal operation begins if no diagnostics have been generated.

Loop Enable/Disable

The proportional, integral, derivative (PID) control loop in the controller can be enabled by either
the binary input (BI1) on the board or by a communicated signal. The communicated signal has
priority over the hardware input. The PID loop is enabled if the communicated signal is invalid and
nothing is connected to the hardware input (refer
Table 6.
Communicated Signal
(nviLoopEnable)
Enable
Disable
Not valid
Not valid
Not valid
If the PID loop is enabled, the controller compares the input to its setpoint and calculates an output
between 0% and 100%. The controller takes that PID output value and controls the outputs
appropriately. If the PID loop is disabled, the outputs go to predefined positions. Refer to the
section,
28
Temperature
Percent
Pressure
Flow
Parts per million (ppm)
10-second wait will be applied.
actuator output is overridden to closed and generates a Process Input Failure diagnostic.
Loop enable summary
"PID Control," p. 29l.
toTable
Hardware Input (BI1)
Does not matter
Does not matter
Enable
Disable
Invalid
6).
The PID Loop Is...
Enabled
Disabled
Enabled
Disabled
Enabled
CNT-SVX08F-EN