Whenever 2 or more data radios are installed to communicate wirelessly, a vital design point is to establish that the radios are in communication with one another.\u00a0 Another design point to verify is that the effective radio signal path is sufficiently robust to provide reliable and consistent communications.\u00a0 Both of these objectives can be realized by becoming familiar with and utilizing the PING feature in any Raveon data radio modem.<\/p>\n
The PING of a remote radio is very similar to the PING of a remote IP address.\u00a0 In each case, the PING command is issued from a local device, the address of the remote device is specified, and if successful, the remote device automatically responds to the PING with the local device displaying the results.\u00a0 For a PING to be successful, communications in both directions between the local and remote device must take place.\u00a0 If a PING fails, one or both directions of communications may be assumed to have failed.<\/p>\n
To PING a remote Raveon radio modem, several conditions must be met.\u00a0 First, both devices must be set to operate on the same frequency (ATFR, ATFT, ATFX parameters) the same bandwidth (ATBW parameter) and the same over-the-air baud rate (ATR2 parameter).\u00a0 \u00a0Next, both radio modems must be operating in packet mode (ATMT parameter set to 0) and have unique valid addresses (MYID or ATMY, TOID or ATDT, and ATMK parameters).\u00a0 Additionally, as PING is a Remote Procedure Request (RPR) that includes a message return from the remote radio ensure that TDMA channel access is disabled and the radios are operating in CSMA (Carrier Sense Multiple Access) mode. If you have a GPS enabled radio setting GPS mode 0 will accomplish this.\u00a0 Finally, both radio modems should have remote access enabled (ATRV parameter set to 0).<\/p>\n
To PING a radio modem, enter into command mode on the local modem and issue the following command:<\/p>\n
PING XXXX<\/p>\n
Where XXXX is the 4 digit address of the remote device (e.g. PING 1002).<\/p>\n
Alternatively, you may utilize Raveon\u2019s free-to-download Windows GUI radio configuration utility Radio Manager.\u00a0 The PING execution is found on the interaction tab.<\/p>\n
When the remote radio modem responds to a PING, and the response is received, the local radio modem will display a brief result without indication of error and include the RSSI (Relative Signal Strength Indicator) signal level of the responding (reply) transmission.\u00a0 To capture the RSSI of the outgoing (request) transmission, you must initiate the PING from the opposing radio, and capture the RSSI from this response.<\/p>\n
Here is an example of a successful\u00a0 PING.\u00a0 In this case the PING is from modem 1001 querying the remote modem 1002:<\/p>\n
Ping 1002<\/p>\n
<RPR><\/p>\n
FROM=1002<\/p>\n
-90<\/RPR><\/p>\n
In the successful PING please note that an RSSI value of -90 is returned.\u00a0 This RSSI information can prove quite valuable. -90 means the receive signal strength was -90dBm.<\/p>\n
Whenever installation trouble is encountered, and two radios do not appear to be communicating, it is a good idea to try and execute a PING. \u00a0If the PING succeeds, you have verified that the two radios are in fact communicating, and you may consider other aspects of the system as potential failure points.\u00a0 A PING can also be a valuable tool in aligning directional antennas, which should accurately point towards the opposing target.\u00a0 While RSSI numbers are relative, generally an RSSI with a value closer to zero than -100dB (i.e. -97, -85db) will be strong enough to support good radio communications.\u00a0\u00a0 Note that this is not strictly the case, especially in environments where there is a lot of noise on the frequency in question.\u00a0 You should always look for a 20dB difference or more between your signal strength and background noise.\u00a0 For instance, if you background noise level is on average in the vicinity of -115db, you want an RSSI value of at least -95db, with -90, or -85dB being preferred, and providing some buffer against occasional noise spikes.<\/p>\n
To acquire an instantaneous reading of the background noise level, ensure no device in the system is transmitting, and then type the command ATRQ.\u00a0 The background noise level will be displayed.<\/p>\n
To strengthen the signal of a transmission you can consider several actions. First, if the output power on the radio modem is not already set at 100% (ATPO parameter), you can increase the output up to 100%.\u00a0 Second, consider slightly repositioning our antennas, use higher gain antennas, or lower loss or shorter antenna cable.\u00a0 Third, install a power amplifier.\u00a0\u00a0 Raveon can recommend and source several amplifiers.\u00a0 In any case, ensure none of these remedial actions violate your radio license limits.<\/p>\n
<\/p>\n
Author: Larry Topp<\/p>\n","protected":false},"excerpt":{"rendered":"
Whenever 2 or more data radios are installed to communicate wirelessly, a vital design point is to establish that the radios are in communication with one another.\u00a0 Another design point to verify is that the effective radio signal path is sufficiently robust to provide reliable and consistent communications.\u00a0 Both of these objectives can be realized […]<\/p>\n","protected":false},"author":13,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[59],"tags":[71,69,64,68,70],"_links":{"self":[{"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/posts\/1179"}],"collection":[{"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/comments?post=1179"}],"version-history":[{"count":6,"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/posts\/1179\/revisions"}],"predecessor-version":[{"id":1212,"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/posts\/1179\/revisions\/1212"}],"wp:attachment":[{"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/media?parent=1179"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/categories?post=1179"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.raveon.com\/data_radio_info\/wp-json\/wp\/v2\/tags?post=1179"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}