Every technical device has limited performance. For the MiniPLC, the original “soft” limitation, or rather reccomendation, was maximum 120 HW data points, which gives about 3 MCIO modules plus some binary input modules to reach the required I/O mix. In this configuration, and with application software typical for the normal HVAC plants, there is absolutely no problem with memory capacity, I/O bus response, web server response, computation cycle and other parameters.
Our customers discovered soon that there is some unleashed power in the Mini, and started to challenge the limits. When increasing the amount of I/Os (and corresponding function blocks in the IDE which serve them) it must be considered that the web server response is slower, and the refresh time in the clients (such as IDE, OPC server, and SCADA) increases, but everything keeps running.
However, one of the unsurpassable limits is the amount of communication channels:
- there may be maximum 3 channels of the same type, and
- the total amount must be less or equal 5.
So, if we have a COM port with I/O modules, a SMS modem, and three Native SoftPLC channels to read the link from other process stations, this is exactly the limit.
- the total number of connections the MiniPLC is able to keep is 10.
This includes those max. 5 channels plus incoming connection from the clients like Vision, IDE, touchscreen, external web panel, Native channels from other PLCs (!) etc.