FAQs

Check out our list of frequently asked questions to find the answers you're looking for. If you don't see your question, email us here.

What are the default factory settings?
Setting the Baud Rate
Radio Parameters
Multipoint Parameters
Ethernet / IP radio setup
How do I access the setup menu?
Board level serial radios
Enclosed radios except ethernet
Ethernet radios and radios equipped with a Diagnostics Port
Why am I getting framing errors?
How do I choose minimum and maximum packet sizes?
Can I mix 422, 485, 232 and TTL interfaces in the same network?
Can I mix baud rates?
Why am I getting garbled data?
How come the reset button on my ethernet radio doesn't bring up the main menu?
How do I set up HyperTerminal?

List of Figures

Baud Rate
Radio Settings
Multipoint Parameters
Ethernet Settings
Hyperterminal Setting

List of Tables

What are the default factory settings? (top)
Radios generally leave the factory configured in point-to-point pairs. The standard settings for a serial radio are shown in figures 1-4.

How do I access the setup menu? (top)
Board Level Serial Radios:
All board level radios may be placed in setup mode by grounding pin 2 on the 10-pin data port. This may be done either with wire, a push button switch, or with tools such as tweezers. The setup menu will trigger off of the falling edge of the pin being grounded.

You will know that the radio is in setup if:
a) All 3 lights on the radio turn green.
b) The radios setup menu appears in the terminal window.

Enclosed radios Except Ethernet: (top)
All enclosed serial radios can be placed in setup mode by pressing the setup button located on either the front panel (115 and 115H radios) or the back panel (115R, 115RC, 115W, 115WC radios).

You will know that the radio is in setup if:
c) All 3 lights on the radio turn green.
d) The radios setup menu appears in the terminal window.

Ethernet radios and radios equipped with a Diagnostics Port: (top)
All Ethernet radios along with radios that utilize a second port dedicated to diagnostics (FGR and I series radios as of 4-4-2003) can be placed in setup mode by sending a ‘U’ (Capital U) to the diagnostics port at a baud rate of 19200.

You will know that the radio is in setup if:
e) All 3 lights on the radio turn green.
f) The radio's setup menu appears in the terminal window.
Note: This is the only way to place an Ethernet radio into setup mode.

Why am I getting framing errors? (top)
The most common cause of framing errors is due to not having Modbus RTU enabled. Networks that are communicating with Modbus equipment, or are using the Modbus protocol need to be sure to enable the Modbus RTU setting in every radio in the network that is hardwired to a Modbus device.

This is done in menu 1 (Baud Rate Menu) and is setting “B”. This will need to be set to 1 in order to satisfy the timing requirements of the Modbus protocol. If in doubt this feature may be enabled without harm in any network. This feature will only cause communications errors in networks that require this type of protocol when it is not activated. Activating this feature in networks that do not require it will not harm the communications of the network (will not generate communications errors) however slight timing delays may be caused in networks that do not use Modbus protocol.

How do I choose min and max packet sizes? (top)
There are many benefits to setting the min and max packet sizes according to the data that you will be sending through the network. One is that it will increase the efficiency in which the network operates, maximizing the number of data transfers with the lowest power consumption and bandwidth usage. Properly set min and max packet sizes can also help to minimize packet loss and interference problems between radio networks.

To begin there are five questions that need to be answered:
1) What is the minimum amount of data that will be sent from master to slave?
2) What is the minimum amount of data that will be sent from slave to master?
3) What is the maximum data that will be sent from master to slave?
4) What is the maximum data that will be sent from slave to master?
5) How often are you polling, what is the duty cycle?

Refer to the following list of “rules” to choose the proper setting:

1. The total number of data bytes that is sent during each RF packet is equivalent to the minimum packet size from table 1, combined with the max packet size from table 2 or 3.

This means that with default settings of:
(1) Max Packet Size 8
(2) Min Packet Size 9
(4) RF Data Rate 3

The total number of bytes sent per RF packet is equal to:
(Min packet size (9) for RF data rate of 3 in Table 1) 44 + (Min packet size (9), Max Packet size (8) in Table 2) 172. = Totaling 216 Bytes per RF packet (44+172=216).

2. The master and slave are BOTH GUARANTEED to send the number of bytes per RF packet that is reflected in Table 1.
3. If needed, the master radio may allocate up to, but not more than, the number of bytes defined as the max packet size as defined in Table 2 or 3.
4.The remaining bytes after the master’s transmission are available to the slave to send data back to the master. If the slave does not have any or enough data to fill the remaining bytes, the transceiver goes into idle mode for the remainder of the transmission.
Using the default settings a master radio MUST send a minimum of 44 bytes, but if need be, can send up to 172 bytes. In a situation where the master radio sends 100 bytes, the slave will send the remaining 116 bytes.

A real life example would start with answering the 5 starting questions:

1) What is the minimum amount of data that will be sent from master to slave?
20 Bytes.

2) What is the minimum amount of data that will be sent from slave to master?
27 Bytes.

3) What is the maximum amount of data that will be sent from master to slave?
25 Bytes.

4) What is the maximum amount of data that will be sent from slave to master?
102 Bytes.

Apply these parameters along with an RF data rate of 3.

First, choose a min packet size, from Table 1, which fills both requirements for questions 1 and 2. Keep in mind that the largest minimum packet size needs to be accommodated. The min packet setting of ‘5’ will give a guaranteed minimum 28 bytes of transferred data which satisfies the requirement of the 27 bytes transferred from slave to master. Obviously the 20 byte minimum from master to slave is covered.

Next, choose a Max packet setting that will provide sufficient transfer for the largest packet size. In this case that is 102 bytes from slave to master.

A max setting of ‘5’ will provide 108 bytes for the maximum packet size. This guarantees the 102 bytes of the slave to master transmission will be satisfied.

(1) Max Packet Size 5
(2) Min Packet Size 5
(4) RF Data Rate 3

These settings will provide the most time efficient packet lengths for this application

Table 1 - Min. Packet Size RF Data Rates (top)

Min. Packet Size RF Data Rate of 3 (top)

 Table 3 - Max. Packet Size for RF Data Rate of 2 (top)

Can I mix 422, 485, 232 and TTL interfaces in the same network? (top)
In a FreeWave® radio network it is common to mix baud rates, as well as interface protocols. This means that it is possible to mix multiple RS232, RS485, RS422, and TTL radios. The only requirement is that the end device interface matches the interface that the radio is setup to use.

It is important to understand that the radio network will strip off all parity, start and stop bits, as well as protocols and then encrypts the data before it is transmitted over the air. The receiving radio will then decrypt and format the data into the appropriate baud rate, parity, and protocol, (that which is set in each radio) before it releases the data out it’s serial port.

This method enables an endless combination of master, repeater, slave/repeaters, and slaves to be mixed in a network.

Can I Mix Baud Rates? (top)
As mentioned previously in the “Can I mix 422, 485, 232 and TTL interfaces in the same network?” section, it is very common to mix baud rates within a network as long as each radios baud rate and parity, as well as protocol (RS232, RS485, RS422, TTL etc.), match the device that it is directly connected to via a cable. The receiving radio in a network will take care of translating the different baud rates, etc. into the appropriate protocol to match its immediate device.

Why am I getting garbled data? (top)
Garbled data has 4 main causes.

1) The baud rate of a radio and its directly cabled device does not match. This will cause every character that is transmitted or received to appear garbled. If you are experiencing complete data garbling, go back and confirm the baud rates of all the devices, and verify that they match their adjoined radio.

2) The parity setting of a radio and its directly cabled device does not match. If most of the data is correct with the exception of a few bytes here and there, chances are that there is a parity mismatch. This will cause every 7th-8th byte for up to 3 bytes after to appear garbled, or incorrect. If you are experiencing sparse data garbling, go back and confirm the parity setting of all the devices, and verify that they match their adjoined radio.

3) Make sure you have the correct interface I.E. a TTL instrument or RTU will not interface correctly with an RS232 radio, and vice versa.

4) The last cause of data garbling is a buffer overflow. This will have very unpredictable outcomes varying from occasional corruption to continuous and complete data corruption. This is caused by lack of flow control lines and is possible at data rates that exceed 38.8 Kbps. Data rates that exceed these data rates need to have flow control lines wired in as well as activated in the software and end devices.

Why doesn't the reset button on my Ethernet radio bring up the main menu? (top)
On the Ethernet series of radios, the reset button on the radio does NOT control the radio, instead it resets the interface board. This may be necessary if at some point of operation it is deemed necessary to reset the internal routing table of the Ethernet interface. In order to place an Ethernet radio a “U” (capital ‘U’) must be sent to the radio via the diagnostics port. This is described in greater detail in the “How do I access the setup menu?” discussion earlier in this document.

How do set up HyperTerminal? (top)
HyperTerminal is the most common serial interface program used to access a FreeWave radio setup menu. It comes standard with all Microsoft operating systems. HyperTerminal (Terminal on Win95) is located in the Start Menu >> Programs >> Accessories >> Communications.

Once the program has been started, create a session with the parameters that match those depicted in Figure 5 and Figure 6.

Once this is complete you may access the setup menu. Refer to the “How do I access the setup menu?” for additional Information on how this is done.