VH-RTU-ECT Veichi VH-RTU-ECT Communication module: EtherCAT communication, compatible with the VH series.

VH-RTU-ECT is a VH-series coupler/communication module with an auto-scanning EtherCAT bus. It is the head of a remote I/O node: the module connects to the head PLC over EtherCAT and relays data onto the local expansion bus, where VH-R and VH-L modules are mounted. Auto-scanning means the master finds the node on the line itself, with no manual address setup.

Typical applications:

• Distributed I/O on large machines where sensors and drives are meters away from the cabinet.
• Coordinated motion on the VH500/VH600 platform that needs a tight cycle and synchronous axes.
• Cutting cable runs: a single EtherCAT cable instead of a harness of signal wires.

Note: EtherCAT is the native bus for Veichi VH controllers (VH500/VH600), so for machines on that platform this is the default version. If the node has to join an existing Profinet plant network, take the VH-RTU-PN version instead. The module provides no I/O of its own — that comes from VH-R and VH-L.

Veichi VH-RTU — communication modules for VH remote I/O

VH-RTU is neither a controller nor an I/O module — it is a set of bus couplers for distributed I/O. In plain terms: when sensors and actuators are spread across a machine or shop floor, instead of running dozens of cables back to the PLC cabinet, you place a separate stack of modules near them and read it over a single bus. VH-RTU is the head of such a remote node: the coupler receives commands over an industrial bus (EtherCAT or Profinet), and behind it sit ordinary VH-R and VH-L expansion modules.

The main reason to choose VH-RTU is cable savings and shorter wiring time on large machines. One bus cable replaces a harness of signal wires, and diagnostics plus hot-swapping of nodes become simpler.

How a remote node on VH-RTU works

• Head station (PLC): a VH500 or VH600 CPU acts as bus master and polls the remote nodes.
• VH-RTU coupler: receives the bus traffic and passes it onto the node's local expansion bus.
• I/O modules: digital and analog VH-R modules go on the right of the coupler; VH-L special boards on the left actually read the sensors and drive the loads.
• Several drops on one bus: each remote node is a separate drop on the line running from the head station.

How the modules in the series differ

In practice the coupler choice is dictated by the network already on site. Building motion on the Veichi VH platform — take the EtherCAT version. Joining an existing Profinet network — the PN version.

What to plan before ordering

• VH-RTU alone measures and switches nothing — it is only a coupler. The real inputs and outputs come from VH-R modules (digital/analog) and VH-L (left special boards).
• You need a compatible head station — usually VH500 or VH600 for EtherCAT. Without a CPU master the node will not run.
• If the I/O is compact and all next to the PLC, a remote node is unnecessary — mount the modules directly on the CPU's right bus.

Our experience with VH-RTU

This is a niche but useful item on large machines and lines where the I/O is spread out over meters. A typical buyer question is what else is needed besides the coupler: the answer is that VH-RTU pairs with VH-R/VH-L modules and a head CPU, so budget the node as a kit. Alongside it on a line, customers often add Veichi VFDs and operator panels.