SNAP PID MODULE REFERENCE
22
SNAP PID Module User’s Guide
Variables Not Requiring Calculation
Values for the PID variables listed in the following table can be entered directly into ioManager
software. It is not necessary to calculate these values in advance.
Variable
Description
Default
To Modify,
Use Mode...
Output
PID output value for analog or TPO outputs.
For
analog output,
this variable is the PID output value
written to the analog outputs, subject to the applicable
output limits.
Range:
0–4095 (0–10 VDC or 4–20 mA)
For
TPO output,
this variable is the TPO duty cycle.
Range:
0 to 100%
0
0%
Manual
Manual
Tune, Proportional
(also called
Proportional Term, P
term,
or
Gain
)
This is one of the four key values for PID loop tuning
(Gain, Integral, Derivative, and Setpoint).
Range:
0.000 to 255.996
1.000
Manual or
Auto
Setpoint
(also called
SP
)
The Setpoint value used in the PID calculation. You can
specify a setpoint value or select an external source for
the value using OptoENET PID Module Tuner software
or ioManager’s PID Module window. See
for more information on PID module
control settings.
Range:
0 to 25000 (in raw counts)
0
Manual or
Auto
Process Variable
(also called
P
)
The Process Variable value used in the PID calculation.
You can specify a process variable value or select an
external source for the value using OptoENET PID
Module Tuner software or ioManager’s PID Module
window. See
“Control Word Bits” on page 18
for more
information on PID module control settings.
Range:
0 to 25000 (in raw counts)
0
Manual or
Auto
Setpoint Lo
(also called
Setpt Low
)
Sets the Setpoint Lo limit. If the Setpoint input is less
than the Setpoint Lo limit, it is clamped to this limit. If
this condition occurs, the Setpoint Lo status flag will
also be set. The Setpoint Lo limit must be less than or
equal to the Setpoint Hi limit, or an error will occur.
Range:
0 to 25000 (in raw counts)
0
Manual or
Auto
Setpoint Hi
(also called
Setpt
High
)
Sets the Setpoint Hi limit. If the Setpoint input is greater
than the Setpoint Hi limit, it is clamped to this limit. If this
condition occurs, the Setpoint Hi status flag will also be
set. The Setpoint Hi limit must be greater than or equal
to the Setpoint Lo limit, or an error will occur.
Range:
0 to 25000 (in raw counts)
27500
Manual or
Auto
Process Lo
(also called
PV Low
)
Sets the Process Lo alarm. If the Process Variable input
is less than the Process Lo alarm, the Process Lo and
Process Quality flags are set. This occurs when the PID
is calculated. The Process Lo alarm must be less than
or equal to the Process Hi alarm.
Range:
0 to 25000 (in raw counts)
0
Manual or
Auto
