The balance of performance and cost, particularly in the choice of a machine controller, is an important factor for small and mid machine builders. Case in point is the F-series PLC family from Triangle Research. The F2424 PLC has 24 digital inputs, 24 digital outputs and 12 analog I/Os built in, and is expandable up to 256 digital I/Os. It is capable of controlling and/or driving up to three stepper motors with up to 4A per phase at 24 Vdc. Its high speed digital inputs allow up to three quadrature encoders, which can provide both speed and position information.
Programming is done in Ladder and Tri-PLC TBasic using the iTrilogi PLC editor, and the PLC is programmable readily over the internet. Dispense Technologies, Brighton, Michigan, uses the PLC for automated process control in the dispensing of sealants and adhesives. The company primary interest was to get away from industry standard PLCs. The programming software for this product allows a combination of ladder logic and written program code allowing us more flexibility and ease programming. The compiled programs remain secure, which reduces the risk of curious machine operators corrupting the code.
Blockwise Engineering, Phoenix, chose the PLCs for machines used in medical devices manufacturing. The PLCs control digital I/O read analog sensor directly, provide analog output, provide direction and step signals for stepper motors, and communicate with other devices via RS-485.
Parata Systems, a Durham, North Carolina based company that specializes in pharmacy automation, uses these PLCs in its manufacturing automation equipment to drive small motors with encoders. Low cost and compact size were the primary reasons for selecting the device, and they are easy to interface with PC. It is easy to implement and is a low cost solution to run motors with encoders at various speeds. The PLC hosts a PLC web server and a Modbus/TCP server, it allows up to six simultaneous connections with i-Trilogi, ExcelLink, SCADA, HMI and MS Excel’s web query software.