PM025 – Low Cost GSM SMS IP Alert Remote Monitoring Logger Wireless Telemetry for Analog 4-20mA Digital and  RS232C RS485 Instrumentation

PM025 GSM IP RTU Digital Input Analog 4-20mA RS232 RS485 DIN mount OEM Customise
PM025 GSM Logger Telemetry with Graphic LCD
PM025 App


Model : PM025

Grapic LCD Display
128 x 64 pixel Backlit

Enfora Quad Band 3G GSM

Inputs and Outputs:
8 Protected Dry Contact Input
2 Analog Input (0-5V/4-20mA/0-25mA) [Std]
–OR —
1 NTC Thermistor Sensor

Power Input:
External 7V-28V
External Serial Interface
RS232C or RS485 for Sensor or Meter Interfacing such as Energy Meter, Flow Transmitter, Gas Transmitter, Analyzers.

72mmW x 88mmH x 59mmD

Standard DIN Rail Mount


The PM025 was designed for low cost large quantities deployment opportunity with factory installed serial interfaces (RS232 (default) /485) that can interface to Metering Devices or sensors with either RS2323C or RS485 interface.   Up to 8 dry contact input including counting devices and 2 analog input can be supported.

PM025 has built in datalogging capability for 16,000 points allowing you a historic log of events, input activation, or as a datalogging on timed interval basis.

The Standard Model PM025 has a FCC/CE approved Quad Band 3G/2G Euro GSM Band. Data can operate as client (remote terminal) or as a TCP/UDP Server (customised firmware). Modbus TCP is supported for Data operation enable this unit with work with any SCADA Software

PM025 is small in size and DIN Rail Mount (72mmW x 88mmH x 60mmD) with pluggable screw terminal to ease panel installation and field replacement.  Large datalogging memory of 4MBYTES allows 100,000 points to be logged and the datalog can be downloaded in CSV format via the high speed USB. The datalog memory is semiconductor flash memory requires no battery backup.

The Backlit Graphic LCD display essential parameters including RTU Name, GSM Number, Network Status and Signal Strength, System DateTime, IO status and Sending SMS information. This ease the field maintenance without having to connect Laptop or sending SMS to verify operation even if the GSM device is not register to Network

Built in RS232C Interface (default to System Console Terminal by default) can be optionally factory configure to RS485 that can connects to Metering Devices, PLCs,  Soanar, Water Quality Sensors, Hydrostatic Level Sensor, Pressure Sensors or Weather sensors. Contact us for custom sensor interfaces to your sensors or logger instruments that allows the PM025 to be used as a remote wireless gateway or SMS alert unit

It has 8  protected Dry Contact Input,  and 2 Analog Input (4-20mA/(default) or 0-5V) with 12 bit ADC resolution

The 2 Analog input allows accepting of analog sensors readings such as from Temperature/Humidity, Level Sensors, Water Qualties, Weather Sensors etc.

External Temperature panel Meter with user setup display can be added to set Hi Lo Alarm.

Built in USB Interface with HID with a free user friendly Windows Configuration software allows the RTU Alert Unit to be setup easily even by novice users. This eliminate cumbersome Serial port, drivers as well as IP Setup/Security Issues.  Free User Setup program supports WINXP, WIN7 (32bit and 64bit) as well as WIN8 (32bit and 64bit)

PM025 Specification:

5 Digital Input (Dry Contact, Protected)
2 Analog Input (12bit ADC, 4-20mA (default)/0-5V)
1 x RS232C default (optional RS485)
Quad Band GSM 3G/2G Modem Euro Band
USB HID Interface (no driver installation)
Switchable Sensor Power for power saving in battery powered application
Graphic LCD (128 x 64 pixel) display Network, IO status, SMS and Comms Status
Optional Digital Temperature Sensor 0 – 100degC

OEM is Welcome!


Summary Of Features

Powered by 32bit ARM  Risc Controller

End User Alert Mode:   SMS (up to 20 phone numbers)

Support up to 5 Level of Escalations.

Server Alert/Monitoring Mode: SMS, Data, Email

Power Supply: DC 7V to 30VDC.

Power Save Mode: Optional contact factory for custom projects. Basic Model runs at full power

PC Interface: USB HID Interface (no driver installation requires)

Serial Interface: 1 x RS232C (factory installed option for RS485)

Non Volatile Logger Memory: Total of 4MByte  onboard datalogger memory

Battery Backed Real Time Clock/Calender: Minimum 8 Years battery life. Automatic syncrhonised by GSM Network requires no field setup of calender date to local time.

Number Of Handphone and Emails: 2 Group of 10 phone each

SMS Escalation: Supported (up to 5 levels of SMS Repeat)

SCADA HMI: TSCADA Windows  and Web Base Interface. via 3G Data or Text and PDU SMS Format.


Computer Data Center: Monitoring Computer, UPS, PC Server, Water Leak, FM200, Temperature/Humidity.

SCADA System (Water Level, Flood Monitoring, Water Quality (PH, DO, Turbidity, Temp), VOC, TOC and other kind of Sensor Measurement

Weather Stations (Rain Gauge), Slope Movement.

Remote Event Alarm Notification. (UPS, Cold Room, Refrigeration, Electrical, Breaker, Solar Panel, Security Panel, Fire Alarm Panel, Lift Monitoring).


PM025  support dual operating mode :

a) Direct Alert SMS  Message Send to User Handphone.
When Alarm Event occurs, Message are compose and then send directly to user handphone. The number of failed Send SMS can be set to automatically retry sending after a user specified interval. Each User can be alert via SMS . Each Person can be assign to Group, and each group can be assign to combination of inputs that will trigger an alert.
When SMS Acknowledgement is turn on, the user will need to acknowledge SMS or else up to 5 level of SMS will be send at user set intervals. If the SMS are not acknowledge after the maximum duration of acknowledgement windows, the SMS will be escalate to the Escalation group.

b) Server Mode: Send to Testech TSCADA CMS Sotware
When Alarm Event occurs, Message are compose and compressed and then send to Testech HMI Software running at the customer central monitoring PC equipped with a SMS/GPRS Modem and Broadband IP connection. Testech support BOTH Dynamic IP and Static IP.IP Camera can be added to Testech TSCADA SQL Server.

In logging mode or interface to Metering devices, the PM025 regularly read or poll data and send to server using either compressed PDU format SMS, or using 3G Data for larger payload packet. 

This means that with our RTU you are assure of the best in both world of operating in standalone mode, Server Mode, and BOTH SIMULTANEOUS User+Server Mode by creating different Phone/IP group on the PM025

The important implication is that our RTU is scalable, allowing customer to gradually scaled up the unit of deployment from standalone base to server base.      


User can send SMS (which has to be validated for a existing phone number in the PM025) can be send to querrie or activate the IO Control, as well as checking the system status including Telco signal strength, status of GPRS Connection, turn ON/ Turn off the Digital Output etc.    

SMS Command supports includes allowing remote authorised Handphone to configure, setup, add/edit/enable/disable/delete handphone numbers etc.                    


Up to 2 Group of 10 Phone Each (that is total of 20 GSM Phone Number) can be setup on the RTU (via RS232C or Keypad)

Group can be set to Server Mode (requires TSCADA HMI Software) or User Mode (direct SMS Message Alert to user Mobile Phone)

Group can be Enable or Disable.

Inputs assignment can be assigned to each Group.  For example if the RTU are connected to mechanical equipments, HVAC and electrical equipment etc and there are different team of maintenance responsible for each category of equipments, you can then alert ONLY the team that are responsible for the particular input that requires service attention when a alarm is send out via SMS

Each group and each individual phone can be individually enable and disable. Inputs can be assigned to different group.


Total of 20 GSM Phone number can be created in the PM025  RTU, by assigning up to 10  Phone Max to Each group (max 2 Groups).

Pm025 Setup Phone

Each Phone can be assign two different privilege mode

Supervisor Phone: Supervisor Phone can configure the unit and send control command to the unit (Turn Alarm ON/OFF, switch RTU to Online GPRS Mode, Switch RTU to OffLine SMS Mode,  Turn Relay On, Snap Pictre, Change Phone Number, Enable/Disable Phone, Enable/DIsable Group)

User Phone: User Phone are only allow to receive alarm message via SMS or Poll the System (for example to check the input status again, or health check).


Input Connector using high quality 5.08mm Pluggable Industrial Terminal connectors for fast removable screw connects.


Each Input can be individually setup to trigger SMS/EMAIL  on Low, High, Alarm Limit Low or Alarm Limit High.

System and IO Status can be check by sending a SMS message  to check RTU Health Status

System can be ARM, DISARM for maintenance.

Digital Input


Each Analog Input resolutions is 12bit instrumentation grade Aanalog To Dgiital Converter accepts unipolar (4-20mA/0-5VDC switchable).

Each Analog Input can trigger an alert due to High Limit, Low Limits or both.

Hysteresis allows user to change the band of changes that that it allows allowance as the alarm cross the boundary of each Alarm Limits to capture for Analog sensor that hover around the limits.

Analog Alarm can be assign to individual group.


Each Channel can be individually configure for zero and span, engineering scaling.

Engineering Scaling: The Low Reading and Full Scale Reading can be scaled to user Engineering Units up to 4 digitals + 1 decimal Place (-9.999 to +999.9)

Low Alarm and Hysteresis: Low Alarm can be set with hysteresis (that is if input falls below the Low Alarm trip point), SMS will be send and the Alarm will only be clear if input recovers to Low Alarm trip point + hysteresis.

High Alarm and Hysterisis: High Alarm can be set with hysteresis (that is if input rises above the High Alarm trip point), SMS will be send and the Alarm will only be clear if input recovers to Low Alarm trip point + hysteresis.


The ADC can be calibrated by the user by using a Process calibrator. Each ADC has 2 points digital calibration for the best linearity. During calibration, the value read in are compare against against accept value.

PM025 uses FULL Digital calibration and there is no TrimPot or Potentiometer. Therefore the long term stability of ADC reading is very good.

Flexible calibration method allows to calibrate:_

a) 2 Points Process Calibrator or voltage generator.
b) User Input 2 Points Value.
C) From User defined calibration base on sensor calibration certificate.

USB Windows Interface

The PM025 is unique in the sense that it has a built in USB HID (Human Interface Device) that is supported by all version of windows since windows XP, Vista, Windows7. This allows fast communicaton interface to PC and supported by a free windows configuration software that allows even novice users to be able to setup the RTU with ease.

Changes made can be save into PM20 interval Non Volatile Memory to permanently store the setup.


All Event (System Login, System Reset, IO Event, Send SMS Operations etc) are logged and save in battery backup memory. By Default, up to 100 event are individually time stamped and store in the event log in the internal non volatile Flash Memories, and using the additional built in 2MByte Non Volatile Flash Memories, unlimited event log is possible.

RS232C / RS485

The PM025  has a  External RS232C (factory installed option to change to RS485) to allow interface to external Metering Devices, Sensors, PCs., Please talk to us for any custom interfacing including ModBus Protocol, Hart Communication protocol.


The WebBase or Windows Base are SCADA developed by Testech Electronics has allows many units of PM025 to be monitor from one central server using enterprise level SQL server. User Phones/Email are store on the Server, and the unit monitor and logs all the RTU on 24/7 basis.

Specific custom HMI has been developed for Data Monitoring, Water Qualities, Flood level Monitoring, Weather Stations,  Turbidity sensors, Volatile Organic Compound, Rain Gauge etc. Each parameter of the SCADA IOs can be modify to suit user sensors.

TSCADA support DVR and IP Camera for real time streaming videos integrated into the SCADA remote Monitoring.


Contact us for free consultation for your custom projects.

Link to TSCADA