jmoreno555

There are several reasons:1.- I have not worked in PLC for several years, the last one was an Allen-Bradley PLC to automate a crane and the GUI design was a headache.2.- The Siemens LOGO PLC is 10 times more expensive than a Raspberry Pi.3.- If a Raspberry Pi is placed inside an Industrial Cabinet and security care is taken in both Hardware and Software, Raspberry Pi is an excellent competitor against any PLC especially if we take into account the excessive cost of the cards I / O of a PLC (For example if you want to control stepper motors).4.- With NODE RED running on Raspberry Pi you can do almost everything. The TEMPLATE node allows you to program any graphic environment with HTML and CSS and with the FUNCTION Node you can program anything you require in JavaScript.

Hi TerryAny concerns about SD card reliability in an industrial and security type environment?Not really. I had an experience with a Raspberry Pi that was damaged by an electric shock during a storm. The Microcontroller and the chip that handles the USB ports were completely burned, however, the SD card remained intact and was only put in a new Raspberry Pi and the problem was resolved.2) Could you have saved costs by just using indicator lights rather than a TFT in each box?Sure! The TFT was left because it was a customer requirement. I would have put in place LED indicators.3) Since local control access might for non-technical security staff in an 'emergency': would it be better to have a separate quickly accessible (but locked) switch panel to operate the bollard(s) rather than having …

Hi TerryAny concerns about SD card reliability in an industrial and security type environment?Not really. I had an experience with a Raspberry Pi that was damaged by an electric shock during a storm. The Microcontroller and the chip that handles the USB ports were completely burned, however, the SD card remained intact and was only put in a new Raspberry Pi and the problem was resolved.2) Could you have saved costs by just using indicator lights rather than a TFT in each box?Sure! The TFT was left because it was a customer requirement. I would have put in place LED indicators.3) Since local control access might for non-technical security staff in an 'emergency': would it be better to have a separate quickly accessible (but locked) switch panel to operate the bollard(s) rather than having to remove the front cover of the system enclosure?It could be. But you have to take into account the buttons were only placed for a failure of the Raspberry Pi or a failure in the communications network and not for emergency security management.Each bollard has its control box and inside it, there are control buttons. If the communications network fails, it is easier to open my three control boxes, than the 7 control boxes of each bollard.With the scheme you propose, if a Raspberry fails, the switch panel would give them access to the rest of the equipment and security control is lost. But I agree with you that it is annoying to have to remove the cover.RegardsJorge Moreno

I do not know. The scope of my work was to do only the electronic control of bollards. I know that the bollard supplier had to prove that bollards could stop a vehicle.