Build Your Own Gateway Navigation:
Build Your Own Gateway – Welcome
Build Your Own Gateway – Part 1: What You’ll Need
Build Your Own Gateway – Part 2: Installing SVXLink
Build Your Own Gateway – Part 3: Configuring SVXLink
Build Your Own Gateway – Part 4: Connecting To The Radio
Build Your Own Gateway – Part 5: Programming the Radio
Build Your Own Gateway – Part 6: Connecting to the Reflector
Build Your Own Gateway – Part 7: Adjusting Audio Levels
Programming the gateway radio
To program the MTM800e gateway radio, you’ll need to connect your FTDI USB cable to your laptop/PC that’s running the Motorola Tetra CPS.
Ensure your FTDI cable connects to pins 19, 20 and 8 (ground) as per the details above in the PEI Data Connectivity – 3.3V FTDI Cable section.
Ensure the radio is powered off, then you’ll need to jumper pin 6 to pin 13 to put the radio in programming mode. Once the jumper is connected, power the radio on. You’ll notice that nothing appears on the display and the radio appears to be dead. It isn’t though! this is expected behaviour when the radio is in programming mode.
Next, on your laptop/PC running CPS, check which COM port is assigned to your FTDI cable using the Windows Device Manager. Typically this will be COM3 or COM4.
Then, within Tetra CPS go to Tools > Detect Radio on RS232 Port then enter the correct serial port number (e.g COM3) and click Detect
This may take a minute or two. If successful, the dialog box will turn green, and your radio will appear on the right side of CPS. To read your radio, simply right click it and choose Read Radio.
Note: If you’re running CPS on a virtual machine, you may notice that your USB FTDI cable keeps connecting and disconnecting. If this occurs, reconnect it by selecting it from the USB menu in your VM software.
Basic Programming
The basics you’ll need to get your gateway radio (MTM800e) up and running are below.
| Section | Setting | Notes |
| Subscriber Unit Parameters > Radio ISSI | 9999 | This ISSI is used for the gateway radio only. Don’t program this ISSI to any of your other radios. |
| Feature Flags > Direct Mode (DMO) | Ticked | Enables DMO mode |
| DMO Parameters > DMO Address Extension > MCC | 901 | |
| DMO Parameters > DMO Address Extension > MNC | 16383 | |
| DMO Parameters >DMO MNI Partnership List > Country Code | 901 | |
| DMO Parameters >DMO MNI Partnership List > Network Code | 16383 | |
| TalkGroups > DMO > DMO Folders List > Name | DMO | Display name for the DMO folder |
| TalkGroups > DMO > DMO Folders List > Status | Ticked | |
| TalkGroups > DMO > DMO Folders List > Transmission Timeout timer, sec | 300 | |
| TalkGroups > DMO > DMO Folders List > Transmission Timeout warning timer, sec | 280 | |
| TalkGroups > DMO > DMO Folders List > Number of talkgroups in range | 1 | This is the number of channels within the folder to display |
| TalkGroups > DMO > DMO Folders List > Receive Only | Not ticked | |
| TalkGroups > DMO > DMO talkgroup List > Name | TETRA GATEWAY | This is the name of the channel that will appear on the display |
| TalkGroups > DMO > DMO talkgroup List > ID | 1 | |
| TalkGroups > DMO > DMO talkgroup List > Status | Programmed | |
| TalkGroups > DMO > DMO talkgroup List > DMO Folders List | DMO | The folder you created above |
| TalkGroups > DMO > DMO talkgroup List > Communication Type | Direct | |
| TalkGroups > DMO > DMO talkgroup List > Gateway Selection | None | |
| TalkGroups > DMO > DMO talkgroup List > Gateway Address | Blank | This field will be blank |
| TalkGroups > DMO > DMO talkgroup List > Frequency Channel | 439.250 | This is the frequency your radio will transmit/receive at. Be sure to use a frequency within your licensing band. If you cannot enter a frequency above 430, please see the note below. |
| TalkGroups > DMO > DMO talkgroup List > Receive Call to DMO Partnership Networks | User Defined | |
| TalkGroups > DMO > DMO talkgroup List > Network MCC | 901 | |
| TalkGroups > DMO > DMO talkgroup List > Network MNC | 16383 | |
| TalkGroups > DMO > DMO talkgroup List > TMO Mapping | blank | |
| TalkGroups > DMO > DMO talkgroup List > Key Group | NO_KG | |
| TalkGroups > DMO > DMO talkgroup List > Incoming Call security Class | Security Class 1 | |
| TalkGroups > DMO > DMO talkgroup List > Outgoing Call security class | Security Class 1 |
Once you’re ready, write the changes to the radio, remove the jumper between pins 13 and 6, and then wait for the radio to power on.
Note: Increasing the frequency
It is possible to expand the transmit/receive frequency of your MTM800e. Do this at your own risk:
Within Tetra CPS Lab mode > Decimal (D) > cp_net_block > net_data > DMO_range
Change the min and max frequencies to suit. Keep in mind the radio starts to lose sensitivity 5 Mhz above and below the factory range. I have successfully extended both Motorola portable and mobile radios + / – 10Mhz without any adverse effects.
Note: Changing the power level
You can also use lab mode to change the power level of the radio from 3 watts to 400 milliwatts – which can be useful for testing.
Within Tetra CPS Lab mode > Decimal (D) > cp_hwconst_block > hwconst_data > 65 > tx_pwr_class_4l
Set this value to 1 to set power to 400 milliwatts, or 0 to set power to 3 watts.
Build Your Own Gateway – Part 6: Connecting to the Reflector >