Product Overview
The FMR15108 is an 8-channel 151MHz receiver designed for applications requiring reliable wireless control. It features open collector outputs, user-selectable frequencies, and multiple operating modes.
Key Features:
- Eight channel receiver with open collector outputs
- Supply voltage: 12 – 24 Volts AC or DC
- Low current consumption
- Built-in noise or signal strength indicator
- User can select 8 different frequencies
- Momentary, Latching, and Security latching modes are all user selectable
- Easy code setup with dip switch settings
- Optional QM100 bracket available for easy mounting to cases or walls.
- C1015 or C1020 case is also available.
Applications:
- Pump Control
- Long distance panic button
- On/Off applications in agricultural devices
- Security alarm
- Basic Telemetry (e.g., Water level indication)
Description:
This receiver provides eight open collector outputs, with output modes configurable to momentary, latching, or security latching. It allows users to select 8 different narrow-band frequencies and program an unlimited number of transmitters. Utilizing a narrow-band FM 151MHz signal, it can achieve a line-of-sight operating range of up to 5000 metres. The receiver incorporates a crystal oscillator circuit for high frequency stability, ensuring optimal performance.
The physical receiver unit (FMR15108) features a PCB with various components. Key elements include the main receiver module, a 12-way DIP switch for setting a unique 12-bit code, a 4-way DIP switch for selecting operating modes, a signal strength indicator composed of blue LEDs, a 6.000MHz crystal oscillator, and a 6-way screw terminal block for the eight outputs (labeled 1-8). Supply (+, -, Sh A) and Antenna connection points are also present, along with four mounting holes.
Operating Modes
The output relay behavior is determined by the 4-way DIP switch settings, which are user-selectable. The following table outlines the modes:
| DIP Switch (1234) Visual | Mode Description |
|---|---|
| [Visual: 4 switches ON] | "All Momentary": Relay is active only while the correct signal is received. |
| [Visual: 1 ON, 2 OFF, 3 ON, 4 OFF] | "All Latching": Outputs alternate state (ON/OFF) at every correct incoming signal. |
| [Visual: 1 ON, 2 ON, 3 OFF, 4 OFF] | "Momentary & Latching": Outputs 1-4 are momentary, and outputs 5-8 are latching. |
| [Visual: 1 OFF, 2 ON, 3 ON, 4 ON] | "Security Latching on": Outputs remain active until the receiver's supply is momentarily interrupted. |
| [Visual: 1 ON, 2 ON, 3 ON, 4 OFF] | "Momentary & Latching": Outputs 1-6 are momentary, and outputs 7-8 are latching. |
| [Visual: 1 ON, 2 ON, 3 OFF, 4 ON] | "Momentary & Latching": Outputs 1-2 are momentary, and outputs 3-8 are latching. |
| [Visual: 1 ON, 2 OFF, 3 ON, 4 ON] | "Momentary & Latching": Outputs 1-3 are momentary, and outputs 4-8 are latching. |
| [Visual: 1 OFF, 2 ON, 3 OFF, 4 ON] | "Security Latching on": Output 1 is security latching, and outputs 2-8 are momentary. |
| [Visual: 1 OFF, 2 ON, 3 ON, 4 OFF] | "Security Latching on": Outputs 1-7 are latching, and output 8 is momentary. |
Mode Definitions:
- Momentary: Output is active only while the transmitter button is pressed. This is common for automatic gates or garage door openers.
- Latching: Output remains active until the next press of the transmitter button, similar to switching a light on and off.
- Security Latching: Output remains active until power to the receiver is removed, similar to security alarms and fire alarms.
Customised Software: Custom output modes can be programmed for special functions by contacting Elsema.
Coding: The 12-way DIP switch on the receiver sets a 12-bit unique code for the system, which must match the code on the transmitter.
Signal and Noise Indicators
The 151MHz receivers feature five blue LEDs on the board to indicate signal strength. The table below shows the relationship between the number of LEDs illuminated and the received signal level:
| LEDs On | Signal Level | Operating Condition |
|---|---|---|
| 5 LEDs | -70dBm | Very Strong signal, Very Reliable operating conditions |
| 4 LEDs | -75dBm | Very Strong signal, Very Reliable operating conditions |
| 3 LEDs | -80dBm | Very Strong signal, Very Reliable operating conditions |
| 2 LEDs | -90dBm | Strong signal, Very Reliable operating conditions |
| 1 LED | -100dBm | Good signal, Reliable operating conditions |
Noise Strength Indicator: If more than one LED is illuminated without a valid transmission, it indicates noise on the selected frequency. To address this, change the 3-way dipswitch on the receiver module to select a different frequency. The following table details the Dipswitch settings and their corresponding frequencies:
| Frequency | Dipswitch 1 | Dipswitch 2 | Dipswitch 3 |
|---|---|---|---|
| 151.600 MHz | On | On | On |
| 152.375 MHz | Off | On | On |
| 151.775 MHz | On | Off | On |
| 151.400 MHz | Off | Off | On |
| 151.175 MHz | On | On | Off |
| 151.025 MHz | Off | On | Off |
| 150.900 MHz | On | Off | Off |
| 150.825 MHz | Off | Off | Off |
The image associated with this section shows a close-up of the 3-way dipswitch on the receiver board, with the switch set to ON for position 1 and OFF for positions 2 and 3. The "SIGNAL STRENGTH" label is visible above the blue LEDs.
Technical Data
| Parameter | Specification |
|---|---|
| Supply Voltage | 12 – 24 Volts AC or DC. Can use Elsema's AC power pack (12PP-1000). Supply lines should be less than 3 metres long to comply with radio frequency authorities. |
| Current Consumption | 22mA Standby at 12VDC, 35mA if all outputs "On". |
| Receiving Freq | 151.6MHz (8 selectable frequencies. See table above). |
| Operating Temperature Range | -5 to 50°C. |
| Sensitivity | Better than 0.5uV (For output to activate). |
| Type of Demodulation | Narrow-Bandwidth Frequency Modulation (FM). |
| Output | Eight Open Collectors. The chart indicates that eight outputs can be ON simultaneously with each output collector current being 125mA. Outputs can hold 40 Volts in "Off" state. |
| Connections | Supply, Antenna & Outputs - Screw type terminal block. |
| Antenna | 50Ω, 151MHz Antenna, Elsema ANT151M for maximum performance. A piece of approximately 1 metre wire can be used for short range applications. |
| Dimensions | 90 X 70 X 15 mm. |
| Mounting hole size | 3.97 mm or 5/32". |
| Weight | 83g. |
| Microcontroller | Can be re-programmed to suit your customised needs. |
| Useable Transmitters | All FMT151 series (with correct setting on the dip switch). See Transmitter datasheet for details. |
| Useable operating range | Up to 5000 metres, depending on installation and type of antenna used. Recommended Antenna is Elsema ANT151M. |
Products in the Range
Elsema offers a range of 151MHz receivers. The FMR15108 is one of several models:
FMR15101
1-Channel Receiver
[Description of FMR15101 PCB image: Shows a PCB with relays, DIP switches, and terminal blocks for one channel.]
FMR15102
2-Channel Receiver
[Description of FMR15102 PCB image: Shows a PCB with relays, DIP switches, and terminal blocks for two channels.]
FMR15101240
1-Channel 240VAC Supply Receiver
[Description of FMR15101240 PCB image: Shows a PCB with relays, DIP switches, and terminal blocks for one channel, labeled for 240VAC supply and contact ratings.]
FMR15102240
2-Channel 240VAC Supply Receiver
[Description of FMR15102240 PCB image: Shows a PCB with relays, DIP switches, and terminal blocks for two channels, labeled for 240VAC supply and contact ratings.]
FMR15104
4-Channel Receiver
[Description of FMR15104 PCB image: Shows a PCB with relays, DIP switches, and terminal blocks for four channels.]
FMR15108
8-Channel Receiver
[Description of FMR15108 PCB image: Shows the main 8-channel receiver PCB with relays, DIP switches, and terminal blocks.]
FMR1510812R
8-Channel, 12V Supply Receiver
[Description of FMR1510812R PCB image: Shows an 8-channel receiver PCB, likely similar to FMR15108 but specified for 12V supply.]
FMR1510824R
8-Channel, 24V Supply Receiver
[Description of FMR1510824R PCB image: Shows an 8-channel receiver PCB, likely similar to FMR15108 but specified for 24V supply.]
Block Diagram
The following describes the layout and connections on the FMR15108 receiver board:
- Supply Terminal Block: Located at the top, marked with '+', '-', and 'Sh A' for power input.
- Antenna Connection: Point for connecting the antenna.
- 4-Way Dip Switch: Used for selecting the operating mode of the outputs.
- Microcontroller: An Elsema PTY LTD Micro Controller is present, along with a 6.000MHz crystal oscillator.
- 151MHz Receiver Module: The core receiver component.
- 12-Way Dip Switch: Used to set the 12-bit unique code for system security.
- 6-Way Screw Type Terminal Block: Provides connections for the eight outputs, labeled 1 through 8.
- Mounting Holes: Four holes are provided for secure mounting of the unit.
Application Notes
Care should be taken with the solid-state outputs to ensure they are protected from inductive loads. This protection is achieved by connecting diodes across DC inductive loads, such as relay coils. If inductive loads are not properly clamped with a diode, the voltage spikes generated by the relay coil can cause the receiver to lock up. In the event of a lock-up, the power supply to the receiver will need to be removed and then re-connected.
The diagram illustrating this note shows the Supply and Antenna connection points. A protection diode (1N914 or 1N4148) is depicted connected in reverse bias across an inductive load (representing a DC relay coil), with the positive supply connected to the load.
Manufacturer Information
Manufactured by: Elsema Pty Ltd
31 Tarlington Place, Smithfield, NSW 2164, Australia.
Phone: 02 9609 4668
Website: http://www.elsema.com