When you need a Low-cost PLC or a PLC for beginners, the CLICK PLC, will always be your best choice. With years of customers’ requests, we tailored the hardware and features, to be the best Budget PLC for your everyday control applications. Selecting A CLICK PLC system starts with the CPU. There are 31 different CLICK CPUs that differ in I/O, and Communication port options. The first main deciding factor will be in communication ports. There are either Serial only or Ethernet and Serial combination CPUs. Under serial only, there is the Basic PLC that has 8 discrete inputs and 6 discrete outputs, that has on the CPU 2 serial ports. This unit does not have a backup battery. Now, not having a battery backup, just means that the values in your memory addresses will not be retained, in the event of a power loss. Your PLC Program will be retained, on a power loss, as it is stored in EEPROM. Next, is the Standards models, and this adds the backup battery, which also provides a real time clock for programming. This unit also adds an additional RS-485 port, on this unit. Giving you a total of 3 independent serial ports. Next there is the Analog PLCs, that have 4 discrete inputs, 4 discrete outputs, 2 analog inputs and 2 analog outputs, these units also have a backup battery, real time clock with the 3 serial ports. The rest of the CLICK CPUs all have ethernet and Serial in some combination. All of the units have Battery Backup and real time clock. The Basic Ethernet CPU has the ethernet port plus 1 RS-232 port. The Ethernet Standard adds the RS-485 port. The Analog Ethernet also has the rs-485 port and analog inputs and outputs in different configurations. This provides a quick comparison of each CPU types features. Now, each type offers CPUs with either DC or AC Discrete inputs and DC or Relay discrete outputs combinations. Please follow the link provided here for more information. Now that you have chosen your CPU you can either power the CPU with one of these two Power supplies or with another external 24 VDC power supply. If you need more Inputs and outputs you can add up to 8 Expansion I/O Modules to the CPU. Now, these modules are split in DC I/O, AC I/O and Analog For DC I/O there are 12 different modules. They range from input modules, output modules and combo input and output modules. Under AC I/O we have 7 different options. These are also split into input, output and combo modules. Last, we have the Analog modules, which consists of 8 different modules. There are 4 analog input modules that offer 0-20ma, 0-10VDC, Thermocouple or RTD. The analog output modules come in 4-20 or 0-10VDC. There are also to two Analog Combo modules that offer 4 channels in and 2 channel out in either current or voltage. To help in your custom system design, we also have this system builder tool. Select the link in the upper right-hand corner and it will take you directly to the system builder. Here you will be able to design your system and add those components directly to your cart. With CLICK you get the very best in Affordable PLC options, with free Programming software, Free award winning Tech support and free shipping on orders over $49. If you have any question on the CLICK PLC please comment below or Call into our Tech support Team. To see more videos on the CLICK PLC please select this link. Click on this link to subscribe to our YouTube channel for upcoming products and technical solutions.