When you first receive your PXU, there are a few parameters you will need to consider adjusting, while most programming options are not touched by most customers and their applications. This document seeks to highlight the essential parameters any application would NEED to set before installing.
There are many other parameters found within the PXU controller that may be suited to your application as well, which are discussed in detail in our product manual for each option. These are the basic options that any user will need to address regardless of almost any application.
APPLICABLE PRODUCTS
Any PXU series standalone PID Temperature/Process Controller
PRE-REQUISITES
The PXU must be wired to power on terminals 1 and 2. For DC models, positive is terminal 1 and negative is terminal 2.
The input signal must be landed on terminals 11(+) and 12(-) if using a process or thermocouple input. Use pins 10, 11(+), and 12(-) for RTD inputs using terminal 10 for excitation.
IN THIS ARTICLE
These are the major programming sections within the PXU.
Input Parameter Programming:
To access the input menu 1-IN from the main screen:
- Press and hold the P button until you see Tune
- Press P three more times to show CNFP
- Press the up arrow to show 1-IN
- Press P to enter the menu and begin programming
- When you're finished with a given parameter, press PAR to save and move on to the next
Type - Must be set to the appropriate input signal feeding the PXU. Examples include Thermocouple types, RTD coefficients, and Process signals. (Please note: for mA signals only, you will have to install the JP8 jumper inside the unit's case as shown at the end of this article, more detail is in the manual on page 10)
SCAL - Only shown if Thermocouple or RTD was selected in type, sets either oF or oC for the display.
dCPt – Sets the decimal place for the display. For thermocouple inputs, options are either no decimals (0) or tenths place (0.0). Process signals let you set up to the thousandths place here (0.000).
dSP1 & dSP2 - Only available for process signal types, sets the signal scaling for your low and high points of the signal. dSP1 corresponds to either 0/4mA or 0VDC, while dSP2 corresponds to 20mA or 10VDC. Scaling for TCs and RTDs are already set in the unit when type is chosen.
Output Parameter Programming:
To access the output menu 2-OP from the main screen:
- Press and hold the P button until you see Tune
- Press P three more times to show CNFP
- Press the up arrow twice to show 2-OP
- Press P to enter the menu and begin programming
- Same as before, when you're finished with a given parameter, press PAR to save and move on to the next
OPAC - Sets control direction for the output (heating or cooling). Can deactivate Output 2 if assigned for an alarm.
Example: r1d2, the first letter shows r for reverse (heating) control for output 1. The second letter shows direct (cooling) control for output 2. Either one of these can be set to either direction. You can also set this to r1A2 for example, which converts Output 2 to a third Alarm contact.
CTRL - Sets the control mode of the unit, either PID or On/Off. If you are using a relay for main control output and you don’t want the relay pulsing constantly, setting this on On/Off will prevent this
CHYS - Sets the reset window for units in On/Off control ONLY. Once the setpoint is reached, the unit will reference this value for how far away from setpoint the signal should drift before activating the output again.
After Programming:
To start an auto-tune from main screen:
- Press and hold the P button until you see Tune
- Press the up arrow to change the option to Yes
- Press P to start the tuning process
tUNE - Only available for PID control, allows the unit to autotune itself obtaining ideally optimal PID values. The duration of a tune is dependent on each individual application, but the PXU will automatically exit the tuning cycle itself after three oscillations.