The DirectLOGIC 305 PLC is a legacy controller that has been available for over 30 years. These CPUs are compatible with most installed DL305 systems.
The DL305 series is a small modular PLC that has been marketed by various name-brand PLC manufacturers for over 19 years.
The D3-350 is the most powerful DL305 CPU. It is a spin-off of our two most powerful CPUs, the D4-450 and D2-250(-1). It is plug-compatible with older bases, as well as analog and discrete I/O modules. The instruction set and I/O numbering scheme are similar to our DL05, DL105, DL205 and DL405 PLCs. The communications capabilities have also been greatly enhanced to now include RS422 Remote I/O, MODBUS Master and Slave protocols, as well as our own DirectNet and K-Sequence protocols.
The D3-330 design has been very popular for many years. It is the lowest-cost solution in the DL305 family and is great for machines that need little (if any) communications between the CPU and other devices.
The D3-330P is similar to the D3-330. There are a few minor differences, but the major difference is that the D3-330P uses the RLLPLUS instructions. This is a style of programming that can be used for larger applications that would function better in stages.
The D3-340 offers a faster scan rate, two RS232C ports (one with built-in MODBUS RTU slave) and additional I/O points.