VC1-2820MDR Veichi VC1-2820MDR PLC: 28 inputs / 20 outputs, relay outputs, 24VDC supply, RS232/485.

VC1-2820MDR — a VC1 CPU module with 28 digital inputs and 20 relay outputs, 24 V DC supply, RS232 and RS485. The DC variant of the large-density I/O CPU.

Typical applications:

• Machines with a single DC supply and 28 sensors.
• Moving and mobile equipment with complex logic.
• Mixed AC/DC loads through relay outputs.

Note: it differs from VC1-2820MAR only in supply (24 V DC). Need a pulse for stepper/servo, take the transistor DC version VC1-2820MDT; for 220 V AC supply, VC1-2820MAR.

Veichi VC1 — compact PLC for series machines and simple automation

VC1 is Veichi's base workhorse series. We reach for it wherever you need to reliably control a single machine or unit: a packaging machine, textile, printing press, doser, conveyor. Up to 16,000 program steps, up to 128 I/O points via modules, RS232, RS485 and USB ports for quick commissioning. For most small-automation tasks this is plenty.

The main reason to choose VC1 is price per function. It is not a motion controller, but three 100 kHz pulse channels and a fast counter let it drive a stepper or servo in simple positioning tasks: cut-off, feed, basic synchronisation.

What VC1 fits

• Packaging and filling: dosing, conveyor, pneumatics — a machine with 16–32 I/O points.
• Textile and printing: winding, material feed, timer-based sequences.
• Small machine tools and woodworking: button, limit-switch and relay logic plus one or two pulse channels.
• Retrofitting an old PLC: revive a legacy machine cheaply without moving to an expensive platform.

How VC1 differs from the higher series

In practice VC1 covers simple machine logic. As soon as you need built-in Ethernet or bus motion, it makes sense to look straight at VC3 or VC5.

When VC1 is NOT a fit

• You need bus motion and axis synchronisation — take VC5 or VH500/VH600 with EtherCAT.
• Multi-axis interpolation, electronic cam — that is VH600 territory.
• You need Ethernet out of the box — look at VC3.
• You work in another brand's ecosystem — compare with Delta or Fatek.

Our experience with VC1

VC1 is a steadily popular series among small and mid OEMs that watch machine cost. The typical buyer question is whether it will drive steppers/servos: for simple cut-off and feed, yes; for coordinated motion I recommend a higher series from the start. A few expansion modules (analog, thermocouple, RS485) cover most of the tasks that surface after installation. Customers often pair it with Veichi VFDs on the same machine.