RV-M7 Data Radio Modem Technical Manual
- General Information and Overview
- Specifications
- Electrical Inputs and Outputs
- Serial Port Commands
- Using the M7 Modem – Packet Mode
- Using the M7 Modem – Streaming Mode
- Installation
- FCC Licensing Information
- M7 Diagnostic Provisions
- Tuneup and Alignment
- Skyline Compatibility
- Antenna Information
- Appendix A. Serial Port Hardware
- Troubleshooting
- Mechanical Information
Solutions by Industry
RV-M7 Data Radio Modem Technical Manual
User Serial Port Commands
The serial portion the RF modem is used to send and receive data over the air, as well as to configure the RF modem. In normal operation, the user sends data into the TxD pin of the user port, and this data is transmitted over the air. Received data from another RF modem is output to the user via the RxD pin of the user port. This is the default operating condition of the RF modem. No special characters, hardware control lines, or timing is required to operate the M7 modem.
There is also a “Command Mode” used to program and configure the M7. In the Command Mode, the M7 modem accepts commands via the serial port TxD pin. The commands can be used to change certain internal parameters of the M7 modem as well as to read-out the current configuration and diagnostic statistics.
The M7 modem may be put into a “Command Mode”, by entering a sequence of three plus characters (+++). To keep the M7 modem from unintentionally entering the Command Mode because of the +++ pattern occurring in a stream of data entering the modem, there must be a pause in the data stream before the +++ as well as a pause after the +++ is sent. If either pause is missing, the modem will not enter the command mode.
Using serial communications software such as HypterTerminal, send the 3-character command sequence “+++” while observing times of silence before [BT (Silence Before Sequence) Command] and after [AT (Silence After Sequence) Command] the command characters. The default BT and AT times are 500mS.
The default sequence for entering into AT Command Mode:
1. No characters sent for ½ a second.
2. Input three (3) plus characters (“+++”) within ½ of a second.
3. No characters sent for ½ a second.
When the M7 modem first enters the Command Mode, it sends the phrase “M7” out it serial port, and then an “OK” sequence. The “OK” sequence is a sequence of 4 characters:
An “O”, “K”, <CR>, and <LF> characters (<CR> = ASCII 0D, <LF> = ASCII 0A)
To set a parameter in the M7 modem, enter the Command Mode as described above. Then enter the proper AT command, a space, the parameter, and then a carriage return. For Example, to set the address of the M7 modem to 1234, enter the following command:
ATDT 1234 <CR>.
Once a Parameter is changed, the modem will begin using the new parameter as soon as it exits the Command Mode and returns to its normal operation mode. If the new parameter was saved to non-volatile memory using the ATSV command, then the new parameter will be used as well the next time the M7 modem is powered on.
If a parameter is changed, but the ATSV command is not issued, the new parameter is used to operate the modem, but when power is turned off and back on, upon powering up, the M7 will revert back to the previously saved parameter value. If parametric changes are to be permanent, always issue the ATSV command after all parameter changes have been made.
To read the value of a particular setting, issue the command, with no parameter. The modem will return the value followed by an “OK”. The modem’s OK response is:
The value in ASCII decimal format.
A <CR> <LF> (<CD> = ASCII 0D, <LF> = ASCII 0A).
An “O”, “K”, <CR>, and <LF> sequence.
For example, if the user enters the command to read the M7’s modem address and its address was 1234, the user would issue the following command:
ATDT<cr>
and the modem will respond with:
1234 <CR> <LF> OK <CR> <LF>
To get on-line help with a command, enter the command and put a question mark in for the parameter. For example, to see what the ATDT command is for, type ATDT ?. The modem will respond by listing a brief description of the command. To see a list of all commands, type HELP.
If certain parameters within the modem are modified in a manor that causes the modem to cease functioning or if the user cannot enter the command mode via the “+++” method described above, there is a small push button internal to the M7 modem to assist in this case. This CONFIG button may be pressed at any time, and forces the modem into a known operational state. The CONFIG button is located inside the modem. Remove the rear cover, exposing the two circuit boards. The button is in the center of the lower circuit board as shown below.
The default settings that the modem will revert to when the CONFIG button is pressed are:
- Serial port 9600 baud, 8 data bits 1 stop, no parity
- ATCT setting set to 60000 (60 second time-out)
- Serial port on the front of the unit in RS232 mode, 9600bps, N/8/1.
If the unit was configured for RS-485, RS-422, or Ethernet, you must disconnect other devices and use an RS-232 device to configure the M7.
Even though the serial baud rate reverts to 9600 baud when the CONFIG button is pressed and the IO port is RS232, it will revert back to the settings programmed into theM7 modem once the Command Mode is exited.
There are three ways to exit the command mode. They are:
1. ATSV Issuing the ATSV command saves the current configuration to non-volatile memory, and then returns to the normal operation mode.
2. ATCN Issuing the ATCN command does not save the current configuration, but it does cause the modem to continue to operate. If changes to the configuration were done in the Command mode, these changes will be used in operation, but they are not be saved to non-volatile memory. The next time the modem is powered down and back up, the modem will operate with the previously saved settings.
3. Time Out. After a pre-set amount of time (60 seconds is the factory default time), the modem will automatically exit the Command Mode, and continue normal operation. Changes will not automatically be saved. This time-out duration may be set with the ATCT command.
The AT&F command may be used to restore the modem back to the factory-default condition. Use this command with caution, as it will erase all previously configured parameters. It will cause the modem to revert back to the factory-defaults, as shown in the command table, “Factory Default” column. The only parameters that it does not restore to default are the radio type and radio calibration values R0-R9, and RA. This is so that the user may restore defaults, and not have to re-calibrate the radio.
To erase ALL parameters, including the radio type and radio calibration, issue the AT&F 123 command. There should not be any reason do this command, because it will require the radio to be re-calibrated per the factory alignment procedure.
| AT
Command |
Command Description | Parameters | Factory
Default |
|
| AK | Enable/Disable ARQ – When ARQ is enabled, this modem will automatically send an ACK packet back to a modem that sends it data. 0=off, 1=on. | Range: 0 – 1 | 0 (no AKCs sent) | |
| AS | Auto Status Report Interval– Sets the time between auto status reports. Time is in minutes. 0 means disabled. | Range: 0 –56000
(minutes) |
0 (Off) | |
| AT | Silence AFTER Sequence - Sets period of silence after the command sequence characters in mS. | Range:0 – 1000
(mS) |
500 | |
| BD | Baud Rate – Sets serial com port baud rate (bps). Over-the-air (throughput) baud rate is set with ATR2 command.
If a PC’s serial baud rate is set higher than the fixed over-the-air baud rate of the module, hardware handshaking may be required. |
Range: 0 – 7
0 = 1200 5= 38400 1 = 2400 6=57600 2 = 4800 7=115200 3 = 9600 4 = 19200 |
3 | |
| BC | Busy Channel Lock Out – Enable/disable the BCL. If enabled, the modem will not transmit on a radio channel that is busy (has RF on if). 0-OFF, 1=ON. | Range: 0-1 | 0 | |
| BT | Silence BEFORE Sequence – Sets period of silence before the command sequence character in mS. | Range: 0-1000
mS |
500 | |
| CH | Configure Hardware Flow Control – Enable (1) or disable (0) flow control. When enabled, the modem will monitor the RTS line, and if it is negated, stop sending data out the serial port. If disabled, the modem will ignore the state of RTS, and always send out charators. | 1 = Enable 0 = Disable |
0 | |
| CN | Exit AT Command Mode – Exits module from AT Command Mode and returns it to Idle Mode. Parameters are not saved in EEPROM. | none | none | |
| CT | Command Time Out – If no valid commands have been received via the serial port within this time period (in milliseconds), modem returns to normal operation mode from Command mode. If the CONFIG button inside the M7 is pressed, this parameter will be automatically set to 60000. | Range: 100-60000mS | 60000 | |
| DT | Destination Address to call– Sets address of the modem to send data to. Note, this parameter is entered in HEX format. Each digit may be a 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,or an F. | Range: 0-FFFF | 1234 | |
| E | Echo – Character echo set on (E1) or off (E0). This applies to the Command Mode only. | Range: 0 , 1 | 0 (no echo) | |
| F | Display frequencies – Display all of the frequencies programmed into all of the channel memories. | N/A | ||
| FT | Transmit Frequency – Program the transmit frequency for this channel. Enter in Hz or in MHz. The frequency will automatically be saved in non-volatile memory (flash) for this current channel number. | Range: See product data sheet. For MURS products, frequency cannot be changed. | See product data sheet. | |
| FR | Receive Frequency – Program the receive frequency for this channel. Enter in Hz or MHz. The frequency will automatically be saved in non-volatile memory (flash) for this current channel number. | Range: See product data sheet. For MURS products, frequency cannot be changed. | See product data sheet. | |
| FX | TX and RX Frequency – Program the receive and transmit frequency for this channel. Enter in Hz or MHz. Same as issuing an ATFR and an ATFT command. The frequency will automatically be saved in non-volatile memory (flash) for this current channel number. | Range: See product data sheet. | N/A | |
| HP | Channel Number – Select separate channels to minimize interference between multiple sets of modules operating in the same vicinity. | Range: 1 - 6 | 1 | |
| IO | Configure the I/O The proper hardware option must be installed in the modem. AllM7 modems support RS-232 mode. | Range: 0 - 5 0=RS232 1=Ethernet 2=RS485 dup 3=RS485 simplx 4=RS422 5=GPS | 0 | |
| IC | Read Current Draw Read the current draw in mA. Accuracy is within 20% of actual current draw. | Range: 0-9999 | N/A | |
| L | Enable/Disable the LEDs – 1 = LEDs always off. This reduces some power consumption. 0 = LED operate normally. | 0 or 1 | 0 | |
| MA | Monitor Address – – Configures the address that Auto-Status transmissions are sent to. Only used if Auto Status is enabled. Each digit may be a 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,or F. Note: FF is interpreted as a group. See addressing section. | Range: 0000 - FFFF | FFFF | |
| MK | Address Mask – Configures local and global address space. Each digit may be a 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,or F. In most applications, this is kept at FFFF. | Range: 0000 - FFFF | FFFF | |
| MT | Protocol Select – The over-the-air communication protocol. 0=Packetized mode, 2=Streaming data. | Range: 0-2 | 0 | |
| MY | Unit Address – Configures the individual; address for this unit. Each digit may be a 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,or F. Note: FF is interpreted as a group. See addressing section. | Range: 0000 - FFFF | 1234 | |
| NB | Parity – Selects parity format. Settings 0-4 transfer 8-bits over antenna port and generate the parity bit on the RF receiving side. | Range: 0 – 5
0 = none 1 = Odd 2 = Even 3 = Mark (1) 4 = Space (0) |
0 | |
| ND | Number of Data Bits – Set/read the number of data bits. | Range: 5 - 8 | 8 | |
| NS | Stop Bits – Selects the number of stop bits. | Range: 1-2 | 1 | |
| PE | Packet Error Display – Shows statistics to compute packet-error rate. Displays Packets Per Minute (PPM) and a running total. | None (display PER)
1 = reset counters |
None | |
| PO | RF Power Output. Set or show the RF power output setting. Value is in percent, from 0% to 100%. Use and RF wattmeter to confirm the power setting, and adjust the % accordingly to obtain the desired RF power level. | 0-100 | 100 | |
| PC | Read TX Current. Read the device’s current draw during the last transmission, in mA. | 0-9999 | - | |
| R0 | Symbol Peak Deviation – Set the peak FM deviation of the transmit symbols. Note: This can be a negative number to invert the modulation. | Range: -1000 – 1000 | 120** | |
| R1 | Select CD pin output signal – CD may be RF carrier detect, or modem data detect. | Range : 0 - 2 2 = Always assert CD 1 = Data CD 0 = RF CD |
1 | |
| R2 | Over-The-Air bit rate - This is the data rate the radio uses to send data over the air. All RF modems in the network must use the same over-the-air baud rate. Refer to section 9.1 for information on how to set the OTA baud rate. | Range: 0 = 800 5 = 9600 2L 1 = 1200 6 = 19200 4L 2 = 2400 7 = 5142 2L |
3 | |
| R3 | Serial Port time out – Number of mS of no activity on the serial port before transmitting the data in its buffer. | Range: 1 - 5000 | 20 (mS) | |
| R5 | Preamble length – The number of bytes to send over-the-air in the pre-amble. | Range: 3 - 255 | 4** (Varies based on data rate and radio type. 7 typical) |
|
| R8 | Frequency Offset. Used to set the radio on the center of the radio channel. | Range: -500 to +500 | 0** | |
| R9 | Modulation Balance. | Range: 0-100 | 20** | |
| RA | Select RF CD output threshold – This value is the RSSI threshold where the carrier detect is asserted. Note: To force CD always on, set this to 0, and R1 to RF Carrier Detect. | Range : 0-999 |
300** | |
| RB | Number of retries. If this modem does not get an ACK back when it sends data, this is the number of times it will re-transmit the packet and wait for an ACK. 0=disabled feature. | Range: 0-99 | 0
(ACKs are not used) |
|
| RF | RF Carrier Required – When enabled, there must be RF energy on the channel for the modem to output data. Streaming data mode only. 1-RF required. 0=ignore rf energy when receiving. | Range: 0, 1 | 0 (no RF required) | |
| RG | Transmit Time-Out-Timer – Sets the transmitter time-out-timer in seconds. This is a fail-safe timer for improper configuration or operation of the modem. In normal operation, the TOT setting is not changed. | Range: 0-999 (seconds) |
60 | |
| RQ | Receiver Signal Level – Reads the Receiver Signal strength this instant, and returns the level in dBm. | Range: -40 to –130 (dBm) | - | |
| RS | RSSI (Receive Signal Strength Indicator) – Returns the signal level of last received packet. The reading is in dBm. Usable for relative comparison of signals, but absolute value is within10dB at -90dBm. | No parameters. Returns a number : -50 to –140 (dBm) varies by model. | none | |
| RT | Radio Type – Select the type of radio module installed within the modem. If this parameter is changed, you must fully recalibrate the modem. The type of radio module installed is listed on the serial number. Various | Range: 1-9 0 = RV-M7-Ux 1 = RV-M6-Vx |
2** |
|
| RV | Disable Remote Access – When enabled (set to a 0), the modem will respond to over-the-air RPR requests, Pings, and over-the-air commands. Default is OFF (1). | 0 = Remote Access on 1 = Remote Access off |
1 | |
| SL | Serial Number – Reads and returns a unique serial number for thjs unit. | Read Only
1 - 999999999 |
unique | |
| SH | Show – Display the configuration of the modem. This will return a page of ASCII characters, showing the main configuration parameters. | none | None | |
| SM | LPM Operation Enable – When set to 1, the DTR input line controls the M7’s low-power operation. When set to 0, the M7 will not go into LPM, regardless of the state of the DTR pin. When set to 2, the modem is forced into a low-power mode, disabling the receiver. | Range: 0, 1, 2 | 0 | |
| ST | Statistics – Show the unit’s operational statistics. See Statistics section of user manual. | 0, 1,2, 3, 4, or 5 | None | |
| SV | Save – Save all the parameters to EEPROM. This command must be used if changed parameters are to be stored in non-volatile memory, and used next time the modem is powered up. Modem exits configuration mode after this command is executed. It saves all parameters except the frequency (The frequency is automatically saved when an ATFT, ATFR, or ATFX command is executed) | none | None | |
| TD | Transmit Test Data – When issued, the modem will begin transmitting data. The type of data sent is set in the parameter. Entering a <CR> will terminate the transmission. | 0 = Go back to normal 1 = Random 2 = Hop up/dn one channel 3 = 1010… at ¼ baud rate 4 = TX all 0s 5 = TX all 1s 6 = Test Points ON 7 = Transmit CW 8 = Transmit 1010101… |
||
| TE | Read product temperature – Read the internal temperature of the unit’s circuit board in degrees Celsius. | -40 to +99 | - | |
| TT | Max Packet Size – Set the maximum number of bytes in an over-the-air packet. | 1 - 512 | 80 | |
| VB | Read DC input Voltage– Returns the DC input voltage reading, in mV (12500 = 12.5VDC input). | None | none | |
| VR | Firmware Version – Returns firmware version currently loaded on the module. | Read Only, 3 characters | none | |
| Xn | Show or Configure the Repeat Table – Set the addresses that this unit will store-and-forward data to/from. n = 1, 2, 3, or 4 designating the entry in the table to show or edit.. | Four parameters aaaa bbbb cccc dddd where aaaa=Source Address bbbb = S.A. Mask cccc = Destination Address dddd = D.A. Mask |
||
| XR | Enable/Disable Store and Forward Repeating – 0=disabled, 1 – enabled. | 0 or 1 | 0 (Off) | |
| XT | Read/set repeater delay – Read or set the repeater delay. This is the time between receiving a data packet, and the time the repeater will re-send it. | |||
| &C | Read Current Draw– Restore the factory default values. This command will not erase the calibration values. After this command executes, the modem will still be in the CONFIG mode. | none | ||
| &F | Restore Factory – Restore the factory default values. This command will not erase the calibration values. After this command executes, the modem will still be in the CONFIG mode. | none | ||
** indicates values that are calibrated in the factory and are unit-specific. If the “Radio Type” is changed, these will need to be re-calibrated.
- Other non-AT commands
| SHOW | Show/display an overview of the radio’s configuration. | None | - |
| PING | Ping another modem. Format is PING xxxx, where xxxx is the ID of the modem to ping. If remote access is enabled on xxxx, it will respond. | XXXX | - |
| RPR | Remote Procedure Request. Used to request execution of a command on a remote mode (over the air). See M7 System Protocol manual for information on using this feature. | ||
For the UHF M7, model RV-M7-UC, the main factory defaults are:
Channel 1 464.500 MHz
Over-the-air baud rate: 4800 baud, 2-level
Serial port RS-232, 9600baud, N/8/1
Hardware flow control Off
RF Power Output 100%
Channel number selected 1
Protocol Packetized protocol
