Gemo AR2-A-24VDC-14D-TR-RTC – Expandable PLC / Smart Relay with Transistor Outputs and Real-Time Clock

The Gemo AR2-A-24VDC-14D-TR-RTC is a compact, expandable PLC / smart relay designed for 24 VDC control applications. This model has been offered on our website since 2011 and combines 14 digital inputs, 10 PNP transistor outputs and a battery-backed real-time clock in a DIN-rail mounted controller.

Main specifications

Supply voltage: Nominal 24 VDC, with an operating supply range of approximately 18–32 VDC. Maximum power consumption is 6 W.

Digital inputs: 14 DC digital inputs for 24 VDC control signals. The standard digital input filter time is at least 8 ms for both ON-to-OFF and OFF-to-ON transitions.

Digital outputs: 10 PNP transistor outputs. The transistor outputs are rated up to 32 VDC / 0.3 A maximum. The 250 VAC / 2 A specification used for relay-output AR2 versions does not apply to this model.

Analog input: This particular AR2-A-24VDC-14D-TR-RTC version has no general-purpose 0–10 V analog input.

Analog output: Not available.

Temperature sensor input: 1 input for a 2-wire PTC temperature sensor, covering approximately -50 to +150 °C. This PTC input should not be confused with a standard analog voltage input.

Real-time clock: This RTC version includes a battery-backed real-time clock. Weekly and annual time schedules can therefore be used for applications such as lighting, pumps, HVAC equipment and other time-dependent control sequences.

Programming and control functions

The controller is programmed with GEMO Ladder Editor. The ladder workspace provides 256 program lines, 5 contact columns and 1 output column. Rising-edge and falling-edge functions can also be assigned to contacts.

Programs are transferred through the RS-232 programming interface using a suitable PLC programming cable. The controller provides 32 timers, 32 16-bit counters with up/down counting, 32 offset counter comparators and 16 hysteresis comparator functions.

Ladder scan time: Up to 10 ms.

Timer resolution: Minimum timer setting is approximately 10 ms. Timer accuracy is specified as ±0.1% or 1 digit, whichever is greater.

High-speed counter inputs: Minimum ON and OFF times are approximately 1.25 ms. These inputs may be used for faster counting applications, but they should not be confused with high-speed motion-control pulse outputs.

Servo and step motor control: The AR2-A-24VDC-14D-TR-RTC has no dedicated high-speed pulse output for pulse/direction control of servo and step systems. A dedicated PLC or motion controller should be selected when high-speed positioning pulses are required.

PID control: The controller does not include a built-in PID algorithm. Applications requiring closed-loop PID control should use a controller that provides an appropriate PID control function or a suitable PLC.

Display and operator functions

The unit includes a 2 × 16 character backlit LCD display, three programmable front-panel F keys and a three-level password-protected menu system. Up to 32 user screens with multiple sub-screens can be prepared for displaying process information and operator messages.

Expansion and HMI communication

Compatible expansion modules can be connected through the controller's RS-485 expansion interface. Depending on the selected expansion configuration, the system can be expanded up to approximately 28 digital inputs and 20 digital outputs.

For communication with an external operator panel / HMI over Modbus RTU, the appropriate AR2-S-24VDC-MB1 gateway and compatible controller software are required. The RS-485 expansion port should not automatically be treated as a direct Modbus HMI port.

RS-485 cabling: Use a twisted, shielded 2-core 24 AWG cable. Communication wiring should follow the manufacturer's terminal and termination recommendations.

Environmental and installation specifications

Operating temperature: 0 to 50 °C.

Protection class: IP20 according to EN 60529.

Relative humidity: Up to 80% at 30 °C, decreasing linearly to approximately 50% at 50 °C, non-condensing.

Terminal tightening torque: Maximum 0.5 N·m.

EMC: EN 61000-6-1 and EN 61000-6-3 for the specified operating environment. When the controller is installed in the same cabinet as AC motor drives, frequency inverters, contactors or other electrical noise sources, correct grounding, cable separation and shielding practices should still be applied.

Gemo AR2 programming software and documentation

Download the Gemo PLC programming software – Ladder Editor V2.4 or refer to the Gemo AR2 PLC English user manual for programming, timer, counter and controller configuration information.

For other models, pricing and related information, visit the Gemo price list, Gemo Electronic main page or our PLC product group.

For product selection and technical questions, please use our Gemo contact page or contact us at gemo@otomasyonavm.com.

Important installation notice: Installation, wiring and commissioning of the Gemo AR2 controller should be performed only by qualified technical personnel. Disconnect all power sources before wiring or servicing the unit. Installation must follow the manufacturer's instructions and the electrical and machinery safety requirements applicable in the country where the equipment is installed.