BRUGINE, Padua, Italy, 22 April 2021: Carel said it has widened its range of I/O expansions in the first part of 2021 with the development of a new digital input expansion board. I/O expansions are modules that can be added to a typical air conditioning application, to increase the number of inputs and outputs available on the controller and, consequently, optimise the flexibility and modularity of the solutions, the company explained through a Press release for the purpose of making the announcement of the launch.

Carel said one of the most common uses of the digital input expansion board involves ventilation sections comprising several fans with electronic motors; in this case, the speed of the individual devices needs to be monitored in order to check their operating status and act on the other fans accordingly, if one of them fails. Carel said it has for many years now offered all of the tools needed to support large systems, such as air-handling units or dry coolers, in which the fans are equipped with electronics that communicate via Modbus^®, making it possible to directly monitor their operating status.

However, units that are smaller in size and capacity have simpler and more economical fans that do not feature serial communication and provide a pulse signal based on the rotation speed, which can be read by fast digital inputs, Carel said. This is the basis for the development of its new digital input expansion board, which the company described as an ideal solution for all cases where numerous digital inputs – including fast inputs up to 500 Hz – need to be read, however, while limiting the total number of I/Os and space required, adding only those that are needed.

One typical example involves so-called “in row units” used for cooling data centres. The highly compact units do not require complex device control architecture or specific sensors for their operation, Carel said. These feature a single ventilation section with at least eight fans in parallel, which need to be monitored individually. In this case, reading the signal is a simple and effective way to verify operation, as well as being a more economical solution than installing expensive air flow-rate sensors, Carel said.

The new expansion board, Carel said, features a high number of digital inputs to ensure maximum flexibility in different applications. This is essential on units where the main controller features a limited number of inputs and outputs, while multiple digital inputs need to be connected, for example to detect alarms or various signals.

The entire range of I/O expansions, Carel said, can be integrated into solutions based on the CAREL pCO and c.pCO programmable controller platforms, or into architecture using different controllers.