We previously covered the topic of enthalpy and dew point in our article Enthalpy as it relates to free cooling in HVAC. In today’s article we will go over how to create these points in CBAS.
Continue reading George’s CBAS Tips, May 2020Most Computrols hardware products include various LEDs – these lights can be very helpful in providing visual feedback of various controller conditions and the status of communication channels.
The LX controller features several differences and improvements over the X-line with regards to LED indicator light functions.
Continue reading George’s CBAS Tips, April 2020The easiest way to program Software Points is by going to Hardware View, finding the controller then going to Points. In Editor Mode or in Live Edit you will see a line at the bottom of the points that says Add A Software Point. Click that to add a point.
Note that all the standard Software Point types are there but there are also a few select System Point types. For example, Controller Run Minutes is a Point that counts the minutes that a controller has been running without a reboot. This can be helpful in determining if a controller’s power is being interrupted
Did you know that you can now use 10K Type II temperature sensors in addition to 10K Type III in CBAS? This means that if Type II sensors are in place when retrofitting controllers at a site, you don’t have to change them.
The use of Type II is limited to the LX line of controllers. You must have a CBAS19 version and LX firmware dated January 15, 2020 or later for this to work.
Did you know that Binary Outputs can be locked out if your power supply is inadequate?
If the power being supplied to the controller is inadequate, all binary outputs will be locked in the OFF state until adequate power is returned. This way the controller continues to run, and if you have alarms setup, you will be notified that the equipment did not start. To know for sure whether this is Binary Lockout or your controller is defective, you must check Controller Diagnostics.
The MN-S series of LCD Display Sensors are a popular choice due to their simplicity and flexibility. Did you know that you can also use the sensor to view the serial address of the UNI, VAV or Stat Interface Board that the MN-S sensor is connected to?
We were recently asked if it would be possible to utilize CO2 sensors with the VAV-B in order to control CFM setpoints. At this particular site, they want to add CO2 sensors to some of the VAV-Bs and command the CFM setpoint to the MAX CFM when CO2 gets above 800 ppm. In the VAV-B manual, there is a scenario that explains how to do this when the CO2 sensor is directly attached to the VAV-B. It is located at the end of the manual in Appendix B.
But what if you don’t have any available inputs on the VAV-B and your CO2 sensor is located on a different controller? In this case, the logic to make this happen will have to come from CBAS.
Did you know that you can simulate your logic programming without having to go into Real Mode or wiring up controllers? This can be really handy, especially when testing central plant operation without having to do it live.
When you look at the list of points, either in Text View or Hardware View, you see the point name on the left. To the right of that is the status of the point, and to the right of that is the priority of the point.
In July of 2018, I wrote an article about The Importance of Probe in BACnet. As a quick recap, when you probe a BACnet Controller in CBAS, the resulting probe file allows points to be imported into the database easily with minimum manual data input. Probing also automatically sets some of the BACnet services that the controller supports, like Read Property Multiple and COV (Change of Value). These are two services that can make BACnet communications more efficient.
