The compatibility of HMI
The majority PLC brands have a HMI that matches their PLC and are planned for each other. Generally it is greatest to go with the equal brand HMI as the PLC. Commonly 3 types of HMIs are presented:
•Touch Screens
•Text Based
•Graphic Based
HMI Text Based
This HMI type is limited and is usually utilized on simple machines. They generally provide 2 to 4 rows with approximately 20 characters per row. Some allocate Data to be imbedded into the text so it is possible to adjust basic types of data. The faults can be showed and some have integrated fault handling functions.
HMI Graphic Based
As it involves graphics can be displayed on the screen. The sizes are from 5” to over 21”. Monochrome and Color monitor are provided. The majority of these screens are Touch Based.
Touch Screen HMI
HMIs of Graphic Based are generally Touch Based as well. They really decrease the hard-wired number Selectors or Buttons needed on a machine. This ability lets a HMI program machine to be built in that can be utilized in any country in the world-wide as far as Machine and Manual control functions go. Showing faults are another capability, it is generally good to be capable to give a description of fault using graphics on faults.
Choosing the machine actually only needs a HMI Text Base but to maintain in line with the PLC of Medium Format and the rising global market they will be using a Touch Screen of Graphic with Multiple capability of Language. As stated previously it is good to utilize a HMI that was planned for the PLC but in this case the majority PLC suppliers do not provide Touch Screens that support English and Chinese so they will apply a 3rd party HMI presented by Monitouch. It meets all their needs and has drivers for almost all main PLCs.
I/O Cards
The Inputs and Outputs exist on all devices and machines. The inputs and outputs number need to be decided. The analog also puts into this category, Analog Outputs and or Analog Inputs may be needed. When choosing I/O cards to be utilized in a package of controls they need to see at more than just the points number.
Let’s see at the main cards of I/O presented in the majority PLCs:
Cards of Input: Analog; Digital
Cards of Output: Analog; Digital