Many vendors HMIs, non-invasive ways to monitor them instantly

During the upgrading of machines and production lines, many new infrastructure and vendors came in and make the production infra diversified through many vendors with specific HMIs, or sometimes the contractor who has installed the HMI is not available at the moment, so how is possible to monitor the data shown on  HMIs without intervention the current system, the simple and affordable answer immediately is to use Optical Character Recognition (OCR).

the ordinary way of monitoring sometimes needs cutting the sensor lines and get the value of them, but there is a better way to monitor HMI data and log them in the application and choose what metric can make more value on the monitoring later on, then install more industrial way like Watcher-Jet or Watcher-MQTT to monitor them