DREHMO EX-Actuator – i-matic
The i-matic series is fitted with position and torque sensors which are accommodated in a pressure-proof control unit housing (EEx d) together with the control unit and the local control station with LC display.
Self-monitoring
A self-monitoring process runs continuously in the actuator. To simplify troubleshooting, the process distinguishes between the following messages:
- Hardware fault
- Sensor fault
- Electronics fault
- Software fault
- Electronics temperature exceeded
- Motor temperature exceeded
All malfunctions that occur are recorded chronologically in an error log.
Commissioning / Non-intrusive calibration
The local control station consists of an LC display, 4 buttons and an IR interface or Bluetooth interface as an option.
The actuator can be set and parameterized locally via the pushbuttons without having to open the control system.
Thanks to a clearly structured menu navigation, the setting values can be easily aligned to the valve. Furthermore, all parameters of the actuator can be set easily.
Furthermore, all parameters of the actuator can be set easily.
To prevent operating errors and manipulation, access to the commissioning mode can be protected with a password.
"Fail-safe"
Should the external reference signal fail or the bus communication break down, a user-definable fail-safe position can be set in line with process requirements or, if the parameter “Fail as is” is selected, the actuator can be arrested in the current position.
Phase sequence correction /Single-phase monitoring
This module ensures that the actuator produces the correct direction of rotation for opening and closing the valve, regardless of the sequence in which the three-phase network phases are applied.
Whether the closing direction is to the right or left is defined by remote or local parameterization.
Combi sensor
An electronic position sensor is used for continuous position detection, including the detection of intermediate positions. Interacting with the i-matic control unit, the sensor switches off the actuator when it reaches limit positions that have been electronically programmed and are non-erasable. At the same time the sensor can supply isolated limit position signals and an analogue 4-20 mA position signal.
A second measuring input is used to make an analogue recording of the torque reached, which is then compared and evaluated with settable switch-off values in the control unit. Analogue measurement, signalling and evaluation of the torque is possible while the actuator is running, whereby only the lower detection limit is restricted by the pretension of the torque springs.
Positioner
Modulating actuators are directly controlled by a primary process controller (e.g. pressure, temperature, flow rate) via a 4-20 mA setpoint value. The integral positioner compares the reference signal (setpoint value) with the analogue position signal generated by the actuator (actual value) and corrects the resulting difference. The Xp parameter can be adjusted over a range of 0.5 %…5 % to set the sensitivity of the actuator, optimally adjusting the modulating actuator to the control process.
Power controller
Electrically and mechanically interlocked contactor-type reversers are employed.
Timer
The timer can extend the actuating time over the entire stroke or over a user-definable partial section up to the limit position. The timer operation in opening or closing direction can be configured by parameters. A further parameter determines whether the range for timer operation is specified using an internal setting or using an optional binary input on the interface for remote commands.
Three values are applied for parameterizing the timer operation.
- Pulse time ton (0.5 s to 30 s)
- Pulse time toff (0.5 s to 30 s)
- Start of timer (0 % to 100 % actuator travel)
Valves / Position and torque characteristic curve
The actuator comprises a function for recording the torque characteristic curve (measuring range: 33 % to 100 % of the nominal torque value). The characteristic curves for plant commissioning on the valve and for cold and warm plant commissioning are permanently stored in the actuator.
Either the central visualizing tool or the on-site laptop is used to display the curves.
Characteristic curves stored here can be edited for a needs-oriented maintenance of valves.
Field bus interfaces
The following field bus interfaces are available or in design stage:
- Profibus DP
- Profibus DP-V1
- Profibus DP-V2
- Modbus
Remote parameterization
While the plant is in operation, all settings can be remotely parameterized and permanently overwritten via the bus using the central parameterization and visualizing tool. The original setting can be retrieved with a reset command.
You can either use
- DREHMO-i-matic-Explorer
- SiMATIC PDM or
- FDT / DTM
as a visualization software.
Data memory
Actuator-specific data is recorded in a non-volatile memory. Such data include operating cycles, running times, faults and data required for preventive maintenance.
IR / Bluetooth interface
In addition to the field bus interface, each i-matic actuator is equipped with an infrared port for connecting an "on-site PC". In this way all data (diagnostic files) can be read out, parameters can be set, plus firmware can be downloaded.
With our i-matic-Explorer software tool, operating and setting tasks are made easy. For wireless communication a Bluethooth® interface is available as an option.
