VC-8AD-I Veichi VC-8AD-I Expansion module: 8 current analog inputs, compatible with the VC series.

VC-8AD-I — an analog input module for VC-series PLCs: 8 current channels (4–20 mA). It mounts to the right of the CPU on the local bus. It's chosen where there are many sensors and the signal is a current loop, robust against noise over long runs.

Typical applications:

• Collecting readings from many 4–20 mA pressure, level and flow sensors.
• Distributed measurement points on a large installation.
• Systems with long cable runs where noise immunity matters.

Note: this module is for current; for 0–10 V voltage signals use VC-8AD-V. If you need fewer channels or also an output, see VC-4AD or the combined VC-4AM.

Veichi VC — expansion modules for the VC PLC series

VC is a family of expansion modules, not standalone controllers. They clip onto the right side of a VC-series CPU (VC1, VC1S, VC3, VC5) over the local bus and add what the bare CPU lacks: extra digital I/O, analog channels, temperature measurement and communications. On their own they do nothing — you first need a VC processor module, then you build out the set you need.

The logic is simple: count how many of each signal type the machine needs, then pick modules per type. Digital points come as relay or transistor blocks, 4–20 mA sensors as analog, thermocouples and RTDs as temperature modules. A single VC1 CPU takes up to 15 right-side modules.

How to split VC by function

• Digital I/O: VC-1600ENN (16 inputs), VC-0016ENR / VC-0016ENT (16 outputs, relay or transistor), VC-0808ENR / VC-0808ENT (8 in + 8 out), VC-0004ENRS (4 solid-state relays).
• Analog: VC-4AD (4 inputs), VC-4DA (4 outputs), VC-4AM (2 in + 2 out), VC-8AD-I / VC-8AD-V (8 inputs, current or voltage).
• Temperature: VC-4PT (Pt100 RTD), VC-4PT2 (PT1000/NTC), VC-4TC and VC-8TC (thermocouples).
• Power and comms: VC-24V5POW (24 V power module), VC-RS485 and VC-eNet (RS485 and Ethernet).

Which module for which signal

In practice most machines are covered by two or three modules: a bit of digital plus one analog or temperature block. No need to grab everything — match the modules to the real signals.

When VC modules aren't enough — what to look at

• If you don't have the CPU yet, start with one from the Veichi PLC page — without it the modules are dead.
• You need Ethernet but the CPU has none — add VC-eNet, or step up to a VC3 with a built-in port.
• If you work inside another brand's ecosystem, compare with Delta or Fatek modules.

Our experience with VC

VC modules see steady demand alongside the VC1 and VC3 CPUs. The typical buyer question is "how many modules per CPU" and "relay or transistor": for contactors and lamps we suggest relay, for pulse and frequent switching — transistor. Analog and temperature blocks are often added after installation, once it's clear which signals are missing. The same machine often gets Veichi VFDs and operator panels too.