Automated solution proves recipe for success

Systems integrator Clint Johnson of Control Freaks, has developed an all-Mitsubishi Electric solution for a machine that produces biscuit crumbs, cereal and snack foods.

Getting a consistent mix was difficult; the liquid needed to form pellets tended to cause the entire mix to clog. The system includes two horizontal spiral blade mixers.

These are run backwards and forwards at different speeds to achieve a thorough mix.

Johnson says: "Each product seems to require a unique pattern of fast and slow, forward and backwards. We have stored those profiles as recipes on a Mitsubishi FX3U PLC, which controls a number of 15 kW E700 and D700 VSDs on the mixer axes over an RS485 network." Feedback loops read the current in the motors to gauge the mix consistency.

Several discrete safety zones were defined within the machine and connected with a control system that could determine whether to stop a single zone, several zones or the whole machine. Mitsubishi recommended a single WS Safety Controller. This was networked with the FX plus an E1163 HMI using Ethernet.