February 2022
Installation, Operation and Maintenance Manual
VCIOM-15345-EN Rev. 1
42
Operation
Section 6: Operation
6.5
Actuator Operation Channels
6.5.1
Two-Wire Control with Maintained Contact to Open or Close
Two-wire control mode uses only one contact to control the actuator, with that contact
often being controlled by a relay. Actuator can be configured to OPEN valve either when
contact is closed (digital signal high) or when the contact is open (digital signal low).
Momentary Contact mode (seal-ins activated) is not possible for two-wire control: the
actuator will reverse direction as soon as remote input changes state.
6.5.2
Three-Wire Control with Maintained Contact or Momentary Contact
Three-wire control mode uses two contacts to OPEN or CLOSE the valve. Actuator can be
configured, during setup, for either Maintained Contact or Momentary Contact control
mode. When Momentary Contact mode is selected, valve cannot be stopped in mid-travel
except when an inhibit/interlock, ESD, or emergency STOP signal is present at terminals.
6.5.3
Four-Wire Control with Momentary Contact and Mid-Travel Reversal
Four-wire control mode uses three contacts to OPEN, CLOSE or STOP valve in
mid-travel—Momentary Contact mode being selected automatically. Default
configuration for STOP input is active on close contact.
6.5.4
Network Control Mode
In Network Control Mode, Modbus commands are used to operate the actuator and read
the status registers of the actuator. Actuator Mode needs to be set to Network Mode for
communication with the HOST System.
6.5.5
Analog Control Mode
Analog Mode with electro-mechanical reversing contactor, is capable of handling position
and process control via a 4 - 20 mA input signal, and includes a 4 - 20 mA feedback signal
of position derived from a non-contacting position sensor. Units are available for either
three-phase or single-phase power supplies.
