There are three production versions of firmware in the BAScontrol series. The original BAScontrol release was 3.1.x which provided support for the BAScontrol20 20-point controller and the BAScontrol22 22-point controller each functioning as BACnet/IP servers. The 20-point model supported either four relay or four triac outputs and one 10/100 Mbps Ethernet port. The 22-point model has two switched Ethernet ports and six relay outputs.
With firmware 3.2.x, BACnet/IP client capability was introduced allowing the BAScontrol22C to command or request data from another BACnet/IP server or from a BACnet MS/TP server via a BACnet/IP to BACnet MS/TP router such as Contemporary Controls' BASrouter. This allowed for remote I/O control of external BACnet points.
The BAScontrol22D was built on firmware release 4.0 where operational enhancements were made to improve performance, develop more sophisticated Sedona components, increase application memory space, and to upgrade to BACnet release 15. Below you will see a selection guide for controllers showing installed firmware. The two new models are shown at the bottom of the table.
| Model | Universal Inputs (UI) | Binary Inputs (BI) | Analog Outputs (AO) | Binary Outputs (BO) | Virtual Components (AV/BV) |
Web Points (WC) | BACnet/IP Ethernet Ports | BACnet MS/TP Ports | BACnet Client |
| BAScontrol20 Firmware 3.1 |
8 | 4 | 4 | 4 Relay or Triac |
24 | 48 | 1 | 0 | No |
| BAScontrol22 Firmware 3.1 |
8 | 4 | 4 | 6 relay | 24 | 48 | 2 | 0 | No |
| BAScontrol22C Firmware 3.2 |
8 | 4 | 4 | 6 relay | 24 | 48 | 2 | 0 | Yes |
| BAScontrol22D Firmware 4.0 |
8 | 4 | 4 | 6 relay | 24 | 48 | 2 | 0 | Yes |
| BAScontrol22S Firmware 4.1 |
8 | 4 | 4 | 6 relay | 24 | 48 | 1 | 1 | Yes |
Regardless of the firmware revision, the intent was for all the controllers to retain several common features. All have eight universal inputs configurable for voltage, current (with an external resistor), temperature with built-in 10k type 2 and type 3 and 20k thermistor curves, pulse input, resistance (1 kΩ - 100 kΩ), and contact closure (voltage-free). There are four binary inputs for voltage-free contact closures, and four analog outputs (0-10 VDC). The 20-pt. models provide a choice of four relay or triac outputs while the 22-pt. models have six relay outputs. Relay outputs are rated at 30 V at 2A and intended to switch NEC Class 2 circuits. All models have the same panel mounting footprint.
All models have at least one BACnet/IP 10/100 Mbps Ethernet port. Some models have two ports using a built-in Ethernet switch. The Ethernet port(s) serves both as a BACnet/IP connection to other devices, and as an IP connection for Contemporary Controls BAScontrol Toolset which is used for live programming of the Sedona-based controller. As a web-based controller, configuration of BACnet points and the viewing of channel data is accomplished with a common web browser over Ethernet.
Firmware 4.0 was necessary to introduce MS/TP communication to the BAScontrol series, and it was an opportunity to optimize the controller. The BAScontrol series utilize a single-chip CPU with both RAM and flash along with an external serial flash memory chip. Sedona code is highly efficient not requiring much application memory space but with more complex HVAC applications a bit more memory helps. With the 4.0 upgrade, additional application memory space was created through software optimization. However, during the development process it was determined that more application memory space could be created by simply removing flag bits in the kits.scode file that are not needed with production code. This benefit would also apply to current 3.x firmware. By simply saving and restoring existing 3.x applications using BASbackup (from updated Toolset), this same reduction in memory use will be realized. Overall, optimizing firmware resulted in a memory saving that proved significant to the controller series. These and other benefits occurred with the firmware 4.0 upgrade project: